H2(g)+F2(g)⟶2HF(g) (l)ΔH∘rxn=−546.6 kJ⋅mol−1
2H2(g)+O2(g)⟶2H2O ΔH∘rxn=−571.6 kJ⋅mol−1
calculate the value of ΔH∘rxn for 2F2(g)+2H2O(l)⟶4HF(g)+O2(g)

Answers

Answer 1

The standard enthalpy change for the reaction 2F2(g) + 2H2O(l) ⟶ 4HF(g) + O2(g) is -1154.8 kJ⋅[tex]mol^{-1}[/tex].

To calculate the standard enthalpy change, or ΔH∘rxn, for the given reaction, we can use the Hess's Law of constant heat summation, which states that the enthalpy change for a chemical reaction is independent of the pathway taken between the initial and final states.

This means that we can add or subtract the enthalpies of other reactions to find the enthalpy change of the desired reaction.

We can first use the given reactions to find the enthalpy change for the formation of 2HF(g) from H2(g) and F2(g):

H2(g) + F2(g) ⟶ 2HF(g)                    

ΔH∘rxn = -546.6 kJ⋅mol−1

Next, we can use the given reaction to find the enthalpy change for the formation of H2O from H2(g) and O2(g):

2H2(g) + O2(g) ⟶ 2H2O(l)            

ΔH∘rxn = -571.6 kJ⋅mol−1

To obtain the desired reaction, we need to reverse the second reaction and multiply it by a factor of 2, and also reverse the first reaction:

2H2O(l) ⟶ 2H2(g) + O2(g)                    

ΔH∘rxn = +571.6 kJ⋅mol−1

2HF(g) ⟶ H2(g) + F2(g)                      

ΔH∘rxn = +546.6 kJ⋅mol−1

Now, we can add the two reactions to obtain the desired reaction:

2F2(g) + 2H2O(l) ⟶ 4HF(g) + O2(g)      

ΔH∘rxn = + (546.6 + 2 × 571.6) kJ⋅mol−1      

= -1154.8 kJ⋅mol−1

Therefore, the standard enthalpy change for the reaction 2F2(g) + 2H2O(l) ⟶ 4HF(g) + O2(g) is -1154.8 kJ⋅mol−1. This negative value indicates that the reaction is exothermic and releases heat to the surroundings.

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Related Questions


Analysis:
1. List the 5 metals (copper, iron, magnesium, lead, silver) in order of ease of reduction (most easily
reduced first, least easily reduced last)

Answers

Answer:

Magnesium

Iron

Copper

Lead

Silver

Explanation:

Triglyceride composition of the oil used determines the consistency of the resulting soap. O True O False

Answers

The triglyceride composition of the oil used is an important factor in determining the consistency of the resulting soap is True.

Triglycerides are the main component of oils and fats and are used in soap making to provide the necessary fatty acids that react with lye to form soap. The type and amount of triglycerides used in soap making affect the soap's characteristics, including its consistency. For example, a high percentage of saturated fats, such as coconut oil, can result in a harder and more cleansing soap. On the other hand, a high percentage of unsaturated fats, such as olive oil, can result in a softer and more moisturizing soap.

Here's a concise step-by-step explanation for the long answer:
1. Triglycerides are the primary component of vegetable oils and animal fats used in soap-making.
2. The composition of triglycerides, which consist of glycerol and fatty acids, influences the properties of the resulting soap.
3. Different oils and fats have different fatty acid profiles, which affect the soap's hardness, lather, and moisturizing properties.
4. By controlling the types of oils used, soap-makers can adjust the consistency and properties of their final soap product.

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what is the ksp for the following equilibrium if calcium hydroxide has a molar solubility of 0.0111 m? ca(oh)2(s)↽−−⇀ca2 (aq) 2oh−(aq)

Answers

The Ksp for the given equilibrium is approximately 5.42 × 10^-6.

We are given that the molar solubility of Ca(OH)2 is 0.0111 M. This means that at equilibrium, the concentration of Ca2+ ions and OH- ions will both be equal to x, since each mole of Ca(OH)2 that dissolves will produce one mole of Ca2+ ions and two moles of OH- ions.

To determine the Ksp for the given equilibrium, we need to first write out the balanced equation:
Ca(OH)2(s) ⇌ Ca2+(aq) + 2OH-(aq)
The Ksp expression for this equilibrium is:
Ksp = [Ca2+][OH-]^2
Therefore, we can substitute x for [Ca2+] and [OH-] in the Ksp expression:
Ksp = (x)(2x)^2 = 4x^3
Substituting the molar solubility value of 0.0111 M for x, we get:
Ksp = 4(0.0111)^3 = 6.3 x 10^-6

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ive systematic IUPAC names for each of the following alcohols: OH OH

Answers

To provide systematic IUPAC names for alcohols, a specific molecular structure needs to be given that contains a hydroxyl functional group attached to a carbon atom.

Alcohols are organic compounds that contain a hydroxyl (-OH) functional group attached to a carbon atom. In order to provide systematic IUPAC names for alcohols, a specific molecular structure needs to be given.

For example, consider the alcohol structure CH3CH2CH2OH. According to the IUPAC naming system, the longest carbon chain containing the hydroxyl group is identified, which in this case is a three-carbon chain. The name of the parent alkane is propane.

The hydroxyl group is treated as a substituent, and is named as a hydroxy group. Therefore, the systematic IUPAC name for CH3CH2CH2OH is 1-propanol.

In summary, to provide systematic IUPAC names for alcohols, a specific molecular structure needs to be given that contains a hydroxyl functional group attached to a carbon atom.

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An electrochemical cell is based on the following two half-reactions: oxidation: Sn(s)→Sn2+(aq, 1.50 M )+2e− reduction: ClO2(g, 0.180 atm )+e−→ClO−2(aq, 1.65 M ) Compute the cell potential at 25 ∘C.

Answers

We have the following two half-reactions:Oxidation: Sn(s)→Sn2+(aq, 1.50 M )+2e−Reduction: ClO2(g, 0.180 atm )+e−→ClO−2(aq, 1.65 M )To calculate the cell potential, we use the formula: Ecell = E°cell - (RT/nF)ln(Q)

Where:

E°cell = Standard state cell potential

R = 0.0821 Lkmol^-1K^-1 (gas constant)

T = 298 K

n = Number of electrons transferred in balanced redox reaction = 2 (from the half-reactions)

F = 96485 C/mol (Faraday's constant)

Q = Reaction quotient = [Sn^2+] [ClO2^-] / [Sn] [ClO2]

1. Standard state cell potential (E°cell): Since we have Sn/Sn^2+ and ClO2/ClO2^- half-cells, E°cell = E°Sn/Sn^2+ - E°ClO2/ClO2^-

= -0.76 V - 0.94 V = -1.7 V

2. Reaction quotient (Q):

[Sn^2+] = 1.50 M

[ClO2^-] = 1.65 M

[Sn] = 1 M (assumed, since Sn is solid)

[ClO2] = 0.180 atm = 0.180 M

So Q = (1.50 M) (1.65 M) / (1 M) (0.180 M) = 9:1

3. Substitute into cell potential formula:

Ecell = -1.7 V - (0.0821 Lkmol^-1K^-1 * 298 K) * ln(9)

Ecell = -1.7 V - 0.0613 * ln(9)

Ecell = -1.76 V

So the cell potential at 25°C is -1.76 V

Let me know if you have any other questions!

of the following, which is not a triprotic acid? select the correct answer below: h3po4 ch3co2h h3aso4 none of the above

Answers

The following is not a triprotic acid is  b.H³AsO⁴

A triprotic acid is an acid that has three acidic hydrogen atoms, which can be ionized in stages to produce three hydrogen ions (H⁺) in solution. When a triprotic acid dissolves in water, it releases H⁺ ions in three stages, with each stage producing a progressively weaker acid.

Out of the given options, H³AsO⁴ is not a triprotic acid, it is a polyprotic acid, which means that it can donate more than one hydrogen ion. Specifically, H³AsO⁴ is a tetraprotic acid, which means that it can donate four hydrogen ions. Each hydrogen ion is released in a stepwise manner, making it less acidic than a triprotic acid. In summary, the correct answer is b. H³AsO⁴ is not a triprotic acid, but a tetraprotic acid, It is important to understand the differences between these acids and their ionization behavior in solution, as it can have important implications in various applications.

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periodic trends, place the following bonds in order of decreasing ionic character. Using Sb-Cl P-Cl As-Cl A) As-Cl Sb-Cl P-Cl B) P-Cl As-Cl Sb-Cl C) Sb-Cl As-C1 P- Cl D) Sb-Cl P-Cl As- Cl E) Sb-Cl P-Cl As- Cl

Answers

The correct order from greatest to least ionic character would be option (B): P-Cl, As-Cl, Sb-Cl.

The ionic character of a bond is determined by the electronegativity difference between the two atoms that are bonded. The larger the electronegativity difference, the more ionic character a bond will have.

In this case, we need to compare the electronegativity of the three elements involved in the bonds: antimony (Sb), phosphorus (P), and chlorine (Cl). The electronegativity values for these elements are as follows: Sb = 1.9, P = 2.19, and Cl = 3.16.

Using these values, we can see that the electronegativity difference between Cl and Sb is the smallest, followed by As-Cl and then P-Cl. Therefore, we can expect that the bond between Sb-Cl will have the least ionic character, followed by As-Cl and then P-Cl.

Based on this reasoning, the correct order from greatest to least ionic character would be option (B): P-Cl, As-Cl, Sb-Cl.

In summary, when comparing the ionic character of bonds between different elements, we can use the electronegativity values of those elements to determine the order of increasing or decreasing ionic character. The larger the electronegativity difference between two elements, the more ionic character the bond between them will have.

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Starting with acetylene, show reagents that you would use to prepare each of the following compounds: (a) 1-Butyne (b) 2-Butyne (c) 3-Hexyne (d) 2-Hexyne (e) 1-Hexyne (f) 2-Heptyne

Answers

(a) To prepare 1-butyne from acetylene, the reagent used is CH₃CH₂CH₂Br in the presence of NaNH₂.

(b) To prepare 2-butyne from acetylene, the reagent used is CH₃CHBrCH₂Br in the presence of NaNH₂.

(c) To prepare 3-hexyne from acetylene, the reagent used is CH₃CH₂CH₂C≡CLi followed by treatment with H₃O⁺.

(d) To prepare 2-hexyne from acetylene, the reagent used is CH₃CH₂C≡CCH₂Br in the presence of NaNH₂.

(e) To prepare 1-hexyne from acetylene, the reagent used is CH₃CH₂C≡CLi followed by treatment with H₃O⁺.

(f) To prepare 2-heptyne from acetylene, the reagent used is CH₃CH₂CH₂C≡CLi followed by treatment with H₃O⁺.

Acetylene can undergo several types of reactions to form different alkynes.

(a) To prepare 1-butyne, acetylene can be reacted with 1-bromobutane in the presence of a strong base like sodium amide (NaNH₂) to form 1-butynyl sodium, which is then treated with dilute acid to form 1-butyne.

(b) To prepare 2-butyne, acetylene can be reacted with 2-bromo-2-methylpropane in the presence of a strong base like potassium tert-butoxide (KOtBu) to form 2-butyne.

(c) To prepare 3-hexyne, acetylene can be reacted with 1-bromo-3-hexyne in the presence of a strong base like sodium amide (NaNH₂) to form 1,3-hexadiyne, which is then treated with a mild reducing agent like sodium in liquid ammonia to form 3-hexyne.

(d) To prepare 2-hexyne, acetylene can be reacted with 2-bromo-1-hexene in the presence of a strong base like potassium tert-butoxide (KOtBu) to form 2-hexyne.

(e) To prepare 1-hexyne, acetylene can be reacted with 1-bromo-1-hexene in the presence of a strong base like sodium amide (NaNH₂) to form 1-hexyne.

(f) To prepare 2-heptyne, acetylene can be reacted with 1-bromo-2-heptyne in the presence of a strong base like sodium amide (NaNH₂) to form 1,2-heptadiyne, which is then treated with a mild reducing agent like sodium in liquid ammonia to form 2-heptyne.

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a solution has [h3o ][h3o ] = 3.0×10−5 mm . use the ion product constant of water kw=[h3o ][oh−]kw=[h3o ][oh−] to find the [oh−][oh−] of the solution.

Answers

[OH-] = 1.0 x 10^-9 M. The ion product constant of water (Kw) at 25°C is 1.0 x 10^-14. Therefore, [OH-] x [H3O+] = Kw/[H3O+]. Plugging in the given [H3O+], we get [OH-] = Kw/[H3O+] / [H3O+], which equals 1.0 x 10^-9 M.

Given [H3O+], we can use the ion product constant of water (Kw) to find [OH-]. Kw = [H3O+][OH-], so [OH-] = Kw/[H3O+]. Plugging in the given [H3O+] value, we get [OH-] = Kw/[H3O+] / [H3O+]. Since Kw = 1.0 x 10^-14 at 25°C, we can substitute that in and solve for [OH-]. The answer is 1.0 x 10^-9 M.

In this problem, we're given the concentration of hydronium ions ([H3O+]) in a solution, which is 3.0 x 10^-5 M. We're asked to find the concentration of hydroxide ions ([OH-]) in the solution using the ion product constant of water (Kw).

Kw is defined as the product of [H3O+] and [OH-], which is always equal to 1.0 x 10^-14 at 25°C. Using this equation, we can rearrange it to solve for [OH-]: [OH-] = Kw/[H3O+].

Plugging in the given [H3O+] value, we get [OH-] = Kw/[H3O+] / [H3O+], which simplifies to [OH-] = 1.0 x 10^-14 M / 3.0 x 10^-5 M. Solving this equation gives us [OH-] = 3.33 x 10^-10 M.

Therefore, the concentration of hydroxide ions in the solution is 3.33 x 10^-10 M.

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how would changing the tlc solvent to 80:20 hexane:ethyl acetate effect rf values?

Answers

Changing the TLC solvent to 80:20 hexane:ethyl acetate can affect the separation and Rf values of the compounds being analyzed and may require further optimization to achieve the desired results.



TLC (thin-layer chromatography) is a widely used technique in chemistry for the separation and identification of different components in a mixture. It involves the use of a stationary phase (a thin layer of adsorbent material) and a mobile phase (a solvent) to separate the different components based on their physical and chemical properties. The Rf (retention factor) value is a measure of the distance that a compound has traveled on the TLC plate relative to the distance traveled by the solvent front. It is a useful tool for identifying and characterizing different compounds in a mixture.
The choice of solvent is an important factor in the TLC separation process. Different solvents have different polarities and can affect the separation and Rf values of the compounds being analyzed. In the case of changing the TLC solvent to 80:20 hexane:ethyl acetate, this would result in a more polar solvent system compared to the original solvent. This is because ethyl acetate is a more polar solvent than the commonly used hexane.
As a result of this change, the Rf values of the compounds on the TLC plate may change. Compounds that are more polar and have higher affinity for the stationary phase may have lower Rf values, while less polar compounds may have higher Rf values. It is important to note that the change in Rf values is not always predictable and can depend on the specific properties of the compounds being analyzed.

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Potassium metal reacts with chlorine gas to form solid potassium chloride. Answer the following:
Write a balanced chemical equation (include states of matter)
Classify the type of reaction as combination, decomposition, single replacement, double replacement, or combustion
If you initially started with 78 g of potassium and 71 grams of chlorine then determine the mass of potassium chloride produced.

Answers

The 149.2 grams of potassium chloride would be produced if 78 grams of potassium and 71 grams of chlorine completely reacted.

The balanced chemical equation for the reaction between potassium metal (K) and chlorine gas (Cl₂) to form solid potassium chloride (KCl) is:

2K(s) + Cl₂(g) → 2KCl(s)

This equation indicates that two atoms of potassium react with one molecule of chlorine gas to yield two molecules of potassium chloride.

The type of reaction is a combination reaction, also known as a synthesis reaction. In this type of reaction, two or more substances combine to form a single product.

To determine the mass of potassium chloride produced, we need to calculate the limiting reactant. The molar mass of potassium is approximately 39.1 g/mol, and the molar mass of chlorine is approximately 35.5 g/mol.

First, we convert the given masses of potassium (78 g) and chlorine (71 g) into moles by dividing them by their respective molar masses:

Moles of potassium = 78 g / 39.1 g/mol = 2 mol

Moles of chlorine = 71 g / 35.5 g/mol ≈ 2 mol

Since the reactants have a 1:1 stoichiometric ratio, it can be seen that both potassium and chlorine are present in the same amount. Therefore, the limiting reactant is either potassium or chlorine.

Assuming potassium is the limiting reactant, we can calculate the mass of potassium chloride produced. Since 2 moles of potassium react to form 2 moles of potassium chloride, we can use the molar mass of potassium chloride (74.6 g/mol) to calculate the mass:

Mass of potassium chloride = 2 mol × 74.6 g/mol = 149.2 g

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arrange the species o2 o2 o2- o22- in order of increasing bond length

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When we arrange the species O2, O2-, O2^2-, and O22- in order of increasing bond length, we need to consider the number of electrons in the valence shell of each oxygen atom.

The O2 molecule has a double bond between the two oxygen atoms, and each oxygen atom has six valence electrons. Therefore, the bond length in O2 is shorter than in any of the other species.

Next, we have O2-, which has an additional electron in its valence shell. This extra electron repels the existing electrons, causing the bond length to increase slightly.

The O2^2- ion has two extra electrons in its valence shell, causing even more repulsion and a longer bond length than in O2-.

Finally, the O22- ion has two oxygen atoms with three extra electrons in their valence shells. This creates even more repulsion, resulting in the longest bond length of all four species.

Therefore, the correct order of increasing bond length is: O2 < O2- < O2^2- < O22-.

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The species can be arranged in order of increasing bond length as follows:

o2- < o2 < o22-

The reason for this order is that as electrons are added to the oxygen molecule, the bond length increases due to the increased repulsion between the electrons. So, the oxygen ion with a negative charge (o2-) has the shortest bond length, followed by the neutral oxygen molecule (o2), and finally, the oxygen ion with a double negative charge (o22-) has the longest bond length.

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consider three 1-l flasks at stp. flask a contains nh3 gas, flask b contains no2 gas, and flask c contains n2 gas. in which flask do the molecules have the highest average velocity?

Answers

At STP (Standard Temperature and Pressure), which is defined as 0 °C and 1 atm pressure, all gases have the same average kinetic energy because they have the same temperature. Therefore, the average velocity of gas molecules is inversely proportional to the square root of their molar mass.

The molar mass of NH3 is 17 g/mol, the molar mass of NO2 is 46 g/mol, and the molar mass of N2 is 28 g/mol. Since NH3 has the smallest molar mass, its molecules will have the highest average velocity. Therefore, the molecules in Flask A (which contains NH3) will have the highest average velocity.

To summarize, the average velocity of gas molecules is inversely proportional to the square root of their molar mass. At STP, all gases have the same temperature, so the gas with the smallest molar mass will have the highest average velocity. In this case, NH3 has the smallest molar mass, so its molecules will have the highest average velocity.

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For Practice 18. 5: Which acid in Example 18. 5 would you choose to create a buffer with pH = 7. 35? If you have 500. 0 mL of a 0. 10 M solution of the acid, what mass of the corresponding sodium salt of the conjugate base do you need to make the buffer? How many mols of the corresponding sodium salt of the conjugated base were needed?

Answers

The mass of the sodium salt of A- that we need to add to the buffer is [tex]M \times (0.050 x 10^{(7.35-pKa))[/tex] x V. The number of moles of the sodium salt of A- that we need is simply [tex](0.050 \times 10^{(7.35-pKa))[/tex] x V.

What is conjugate acid?

A conjugate acid is the species that is formed when a base gains a proton (H⁺). For example, in the reaction [tex]NH_3 + H_2O \rightleftharpoons NH^{4+} + OH^-[/tex], ammonia (NH₃) is a base that accepts a proton from water (H₂O) to form its conjugate acid, ammonium (NH⁴⁺).

To create a buffer with pH = 7.35, we need an acid whose pKa is close to this pH. From Example 18.5, we know that the pKa values for the three acids are:
Acetic acid ([tex]CH_3COOH[/tex]): pKa = 4.76
Hydrofluoric acid (HF): pKa = 3.15
Phosphoric acid ([tex]H_3PO_4[/tex]): pKa1 = 2.15, pKa2 = 7.20, pKa3 = 12.35
Of these, phosphoric acid has a pKa closest to the desired pH of 7.35, so we will choose it to create the buffer.
pH = pKa + log([A-]/[HA])
[A-] = [tex][HA](10^{(pH - pKa))[/tex]
[A-] = [tex]0.10 M(10^{(7.35 - 7.20))[/tex] = 0.126 M
So we need a 0.10 M solution of phosphoric acid and a 0.126 M solution of [tex]NaH_2PO_4[/tex] to create the buffer.
To find the mass of [tex]NaH_2PO_4[/tex] needed to make the 0.126 M solution, we can use the formula:
moles = concentration × volume
The volume of the 0.126 M solution we need is:
volume = 500.0 mL = 0.5000 L
So the number of moles of [tex]NaH_2PO_4[/tex] we need is:
moles = 0.126 M × 0.5000 L = 0.0630 moles
The molar mass of [tex]NaH_2PO_4[/tex] is:
(1 × 22.99) + (1 × 1.01) + (2 × 30.97) + (4 × 16.00) = 119.98 g/mol
So the mass of [tex]NaH_2PO_4[/tex] we need is:
mass = moles × molar mass = 0.0630 moles × 119.98 g/mol = 7.56 g
Therefore, we need 7.56 g of [tex]NaH_2PO_4[/tex] to make the buffer.
To find the number of moles of [tex]NaH_2PO_4[/tex] needed, we can use the formula:
moles = concentration × volume
The volume of the 0.126 M solution we need is:
volume = 500.0 mL = 0.5000 L
So the number of moles of [tex]NaH_2PO_4[/tex] we need is:
moles = 0.126 M × 0.5000 L = 0.0630 moles
Therefore, we need 0.0630 moles of [tex]NaH_2PO_4[/tex] to make the buffer.

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how many grams of h3po4 are in 175 ml of a 3.50 m solution of h3po4?

Answers

There are 60.025 grams of H₃PO₄ in 175 ml of a 3.50 M solution of H₃PO₄.

How to calculate the grams of a substance from its molarity?

To solve this problem, we can use the formula:
Molarity (M) = moles of solute/liters of solution

First, we need to calculate the moles of H₃PO₄ in the solution:
Molarity = 3.50 M
Volume = 175 ml = 0.175 L

Moles of H₃PO₄ = Molarity x Volume
Moles of H₃PO₄ = 3.50 mol/L x 0.175 L
Moles of H₃PO₄ = 0.6125 moles

Next, we can use the molar mass of H₃PO₄ to convert moles to grams:

Molar mass of H₃PO₄ = 98 g/mol

Grams of H₃PO₄ = moles of H₃PO₄ x molar mass of H₃PO₄
Grams of H₃PO₄ = 0.6125 moles x 98 g/mol
Grams of H₃PO₄ = 60.025 g

Therefore, there are 60.025 grams of H₃PO₄ in 175 ml of a 3.50 M solution of H₃PO₄.

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Calculate the number of oxygen atoms in a 70. 0g sample of scheelite

Answers

After the finding of molar mass and no. of  moles there are 5.55 × 10²³ oxygen atoms in a 70.0 g sample of scheelite.

The formula of scheelite is CaWO4. The atomic weight of calcium (Ca) is 40.078 g/mol, tungsten (W) is 183.84 g/mol, and oxygen (O) is 15.999 g/mol . To calculate the number of oxygen atoms in a 70.0 g sample of scheelite, you can use the following steps: Step 1: Determine the molar mass of scheelite. Molar mass of CaWO4= (1 × atomic mass of Ca) + (1 × atomic mass of W) + (4 × atomic mass of O)= 40.078 g/mol + 183.84 g/mol + (4 × 15.999 g/mol)= 287.33 g/molStep 2: Calculate the number of moles of scheelite.

Number of moles of CaWO4= Mass of CaWO4 / Molar mass of CaWO4= 70.0 g / 287.33 g/mol= 0.2434 molStep 3: Find the number of oxygen atoms in the sample. Number of oxygen atoms in the sample= (4 × number of moles of CaWO4 × Avogadro's number)= (4 × 0.2434 mol × 6.022 × 10²³ atoms/mol)= 5.55 × 10²³ atoms Hence, there are 5.55 × 10²³ oxygen atoms in a 70.0 g sample of scheelite.

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Helppppplpllllusjssjjs​

Answers

H2O at solid state is very little movement, rigid particles.
H2O at a liquid state is flowy, liquidy.
H2O at a gaseous state is erratic and spread apart

How many grams of NaCl are produced when sodium reacts with 119 grams of chlorine gas? Written in correct form please

Answers

When sodium reacts with 119 grams of chlorine gas, 234 grams of NaCl are produced.

The balanced chemical equation for this reaction is 2Na + Cl2 → 2NaCl. From this equation, we can see that for every 2 moles of Na, 1 mole of Cl2 is required to produce 2 moles of NaCl.

To find the number of moles of Cl2 present in 119 grams, we first need to calculate its molecular weight, which is 70.90 g/mol. Dividing 119 grams by this value gives us 1.67 moles of Cl2. From the stoichiometry of the balanced equation, we know that 1 mole of Cl2 produces 2 moles of NaCl.

Therefore, 1.67 moles of Cl2 will produce 3.33 moles of NaCl. Finally, multiplying the number of moles by the molecular weight of NaCl (58.44 g/mol) gives us the answer: 234 grams of NaCl.

Therefore, when sodium reacts with 119 grams of chlorine gas, 234 grams of NaCl are produced.

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compute the probability of a type ii error when μ = 95.5, if α = 0.07.

Answers

To compute the probability of a type ii error when μ = 95.5 and α = 0.07, we need to first determine the critical value for the test. This critical value is determined based on the level of significance, α, and the sample size, as well as the assumed   standard deviation or the standard error of the estimate.

Assuming that we have all the required information, we can use a statistical software program or a statistical table to find the critical value for the test. Once we have the critical value, we can calculate the probability of a type ii error using the following formula:

P(Type II Error) = β = P(Z ≤ Z_crit + (μ - μ0) / σ) - P(Z ≤ Z_crit + (μ - μ1) / σ)

where Z_crit is the critical value, μ0 is the null hypothesis mean, μ1 is the alternative hypothesis mean, and σ is the standard deviation or the standard error of the estimate.

In this case, we are given that μ = 95.5 and α = 0.07, but we do not have information about the standard deviation or the sample size. Therefore, it is not possible to compute the probability of a type ii error without additional information.

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Which aqueous solution is expected to have a pH less than 7 at 25 degree C? NH_4Br (aq) RbC_2H_3O_2 (aq) MgCl_2 (aq) LiNO_3 (aq)

Answers

The aqueous solution that is expected to have a pH less than 7 at 25 degrees Celsius is NH_4Br (aq). This is because NH_4Br is an ammonium salt and when it dissolves in water, it undergoes hydrolysis to produce H+ ions, leading to an acidic solution.

RbC_2H_3O_2 (aq), MgCl_2 (aq), and LiNO_3 (aq) are not expected to produce an acidic solution, as they do not undergo hydrolysis to produce H+ ions.


Which aqueous solution is expected to have a pH less than 7 at 25°C? The solution that will have a pH less than 7 at 25°C is NH_4Br (aq). This is because NH_4Br is an ammonium salt that will release NH_4+ ions in water. NH_4+ ions will react with water to form NH_3 and H_3O+, leading to an acidic solution with a pH less than 7. The other compounds (RbC_2H_3O_2, MgCl_2, and LiNO_3) are not expected to produce acidic solutions.

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what is the formula of the hydride formed by bromine? fill in the blank 1

Answers

The formula of the hydride formed by bromine is HBr.

Bromine is a halogen element with atomic number 35, and it has a tendency to gain one electron to achieve a stable electron configuration. Hydrogen, on the other hand, has one electron to lose. When these two elements combine, bromine gains an electron from hydrogen, resulting in the formation of a bromide ion (Br^-). Since hydrogen donates its electron, it becomes a positively charged hydrogen ion (H^+). The combination of the bromide ion and the hydrogen ion results in the formation of the hydride compound HBr.

Therefore, the required formula of the hydride is HBr, which is formed by bromine.

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calculate the molar absorptivity (ε) of a 5.0 x 10-4 m solution which has an absorbance of 0.20 when the path length is 1.3 cm?

Answers

The molar absorptivity (ε) of the given solution is 3.08 x 10⁴ L/(mol⋅cm).

The molar absorptivity (ε) is a measure of how strongly a particular chemical species absorbs light at a given wavelength. It is a characteristic of the species, the solvent, and the wavelength of light used.

The molar absorptivity is given by the Beer-Lambert Law, which states that the absorbance (A) of a solution is directly proportional to the concentration (c) of the absorbing species, the path length (l), and the molar absorptivity (ε) of the species, i.e.,

A = εcl

We are given the concentration of the solution as 5.0 x 10⁻⁴ M, the path length as 1.3 cm, and the absorbance as 0.20. Substituting these values in the above equation, we get:

ε = A / (cl) = 0.20 / (5.0 x 10⁻⁴ M x 1.3 cm) = 3.08 x 10⁴ L/(mol⋅cm)

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determine the formal charge on nitrogen in the nitrite ion (no2-).

Answers

The formal charge on nitrogen in the nitrite ion (NO2-) is +1.

What is nitrite ion's formal charge?

To determine the formal charge on an atom, we compare the number of valence electrons it should have (based on its position in the periodic table) with the number of electrons assigned to it in the Lewis structure. In the case of the nitrite ion (NO2-), the Lewis structure shows that nitrogen (N) is bonded to two oxygen (O) atoms and has one lone pair of electrons.

Nitrogen has a valence electron configuration of 5. In the nitrite ion, each oxygen contributes 6 electrons (since oxygen has 6 valence electrons) and the overall charge of the ion is -1.

By applying the formula for formal charge, which is the valence electrons minus the non-bonding electrons minus half of the bonding electrons, we can calculate the formal charge on nitrogen.

Formal charge = 5 - 2 - (6/2) = +1

Hence, the formal charge on nitrogen in the nitrite ion is +1.

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Besides water molecules, what species is/are present at the greatest concentration when NH;(g) is bubbled into water? (Kfor NH3(aq) is 1.8x10-) - (A) NH3(aq) (B) NH OH(aq) (C) NH4*(aq) and OH(aq) (D) NH2 (aq) and H3O+ (aq)

Answers

Option (C) NH₄+(aq) and OH-(aq) is correct.

How to find what speceies are present at the greatest concentration?

To determine the species present at the greatest concentration when NH₃(g) is bubbled into water, it acts as a weak base and reacts with water to form ammonium hydroxide (NH₄OH(aq)). The equilibrium reaction can be represented as follows:

NH₃(g) + H₂O(l) ⇌ NH₄OH(aq)

In the aqueous solution, NH₄OH dissociates into NH₄+(aq) and OH-(aq). However, NH₄OH is a weak base, and its dissociation is limited. Therefore, the predominant species present in the highest concentration would be NH₄+(aq) and OH-(aq).

Option (C) NH₄+(aq) and OH-(aq) is correct.

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How many air molecules are in a 13.5×12.0×10.0 ft room? Assume atmospheric pressure of 1.00 atm, a room temperature of 20.0 ∘C, and ideal behavior.
Volume conversion:There are 28.2 liters in one cubic foot.

Answers

Assuming ideal behavior, the number of air molecules in a 13.5×12.0×10.0 ft room at atmospheric pressure of 1.00 atm and room temperature of 20.0 ∘C can be calculated using the ideal gas law.                                                                                          

First, we need to convert the volume to liters by multiplying it with the conversion factor of 28.2 liters per cubic foot. The volume of the room in liters is 13.5×12.0×10.0×28.2 = 45,864 liters. Next, we can use the ideal gas law equation, PV=nRT, where P is the pressure, V is the volume, n is the number of molecules, R is the gas constant, and T is the temperature in Kelvin. Solving for n, we get n = PV/RT, where R = 8.314 J/mol*K. Plugging in the values, we get n = (1.00 atm)(45,864 L)/(8.314 J/mol*K)(293 K) = 2.01×10^25 molecules. Therefore, there are approximately 2.01×10^25 air molecules in a 13.5×12.0×10.0 ft room.

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What mass of nickel is in a 2,400 g sample of propanol if the concentration is 20 ppb?
A. 0.0083 g Ni
C. 4.8 x 10-5g Ni
B. 0.048 g Ni
D. 8.3 x 106 g Ni

Answers

Answer:

x= 4.8x10^-5

Explanation:

20ppb=20 parts per billion

______20g Ni________ = ____ XgNi___

1,000,000,000g sample      2400g sample

x=_(20)(2400)_ = 4.8x10^-5

       1 billion

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Electrolysis of a solution of Zn(NO3)2 (aq) to give zinc metal is carried out using a current of 2.12 A. How long should electrolysis continue in order to prepare 2.5 g of zinc?

Answers

Electrolysis should continue for approximately 3,682 seconds, or 61.36 minutes, to produce 2.5 g of zinc from Zn(NO3)2 (aq) using a current of 2.12 A. The amount of zinc produced in an electrolytic cell can be calculated using Faraday's law of electrolysis

The relationship between the amount of substance produced, the current, and the time can be expressed as: n = (I x t x M) / (z x F)

where n is the amount of substance produced (in moles), I is the current (in amperes), t is the time (in seconds), M is the molar mass of the substance (in grams per mole), z is the number of electrons transferred per molecule of the substance, and F is the Faraday constant (96,485 C/mol).

In this case, we want to produce 2.5 g of zinc using a current of 2.12 A. The molar mass of zinc is 65.38 g/mol, and the number of electrons transferred per molecule of zinc is 2. Thus, we can calculate the time required for the electrolysis as follows:

n = (I x t x M) / (z x F)

2.5 g / 65.38 g/mol = (2.12 A x t x 1 mol/65.38 g) / (2 e- x 96,485 C/mol)

t = (2.5 g x 2 e- x 96,485 C/mol x 65.38 g/mol) / (2.12 A)

t = 3,682 seconds

Therefore, the electrolysis should continue for approximately 3,682 seconds using a current of 2.12 A.

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What volume of Hydrogen (STP) is produced by dissolving 1. 4 moles of aluminum in sulfuric acid? 2AI (s) + 3H2SO4 = AI2(SO4)3 +H2 Answer in units of L​

Answers

By reacting 1.4 moles of aluminum with sulfuric acid, it produces 1.05 moles of hydrogen gas at standard temperature and pressure (STP). The volume of hydrogen gas can be calculated using the ideal gas law and converted to liters.

According to the balanced chemical equation [tex]2Al (s) + 3H_2SO_4[/tex]→ [tex]Al_2(SO_4)_3 + 3H_2[/tex], we can see that 2 moles of aluminum react with 3 moles of sulfuric acid to produce 3 moles of hydrogen gas. This means that for every 2 moles of aluminum, 3 moles of hydrogen gas are produced.

Given that there are 1.4 moles of aluminum, we can set up a proportion to determine the moles of hydrogen gas produced. The proportion is as follows:

(1.4 moles Al) / (2 moles Al) = (x moles H2) / (3 moles H2)

Cross-multiplying, we find that x = (1.4 moles Al) × (3 moles H2) / (2 moles Al) = 2.1 moles H2.

Since the problem asks for the volume at STP, we can use the ideal gas law, PV = nRT, where P is the pressure (standard pressure at STP is 1 atm), V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature (standard temperature at STP is 273 K).

Substituting the values, we have (1 atm) × V = (2.1 moles) × (0.0821 L·atm/(mol·K)) × (273 K).

Simplifying, we find V = (2.1 moles) × (0.0821 L·atm/(mol·K)) × (273 K) = 47.6 L.

Therefore, the volume of hydrogen gas produced when dissolving 1.4 moles of aluminum in sulfuric acid at STP is 47.6 liters.

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Draw the major organic product from reaction of 1-butyne with BH3 in THF, then H2O2, OH- If no reaction occurs, tell OWL by writing ethane, CH3CH3. Specify stereochemistry when it is relevant

Answers

The reaction of 1-butyne with BH3 in THF, followed by H2O2 and OH-, leads to the formation of 1-butanal as the major organic product.

The reaction of 1-butyne with BH3 in THF, followed by H2O2 and OH-, leads to the formation of 1-butanal as the major organic product. The first step of the reaction involves the addition of BH3 to the triple bond of 1-butyne, leading to the formation of an alkenylborane intermediate. In this intermediate, the boron atom is sp2 hybridized and has a trigonal planar geometry. The addition of H2O2 and OH- to this intermediate leads to the oxidation of the boron atom to a hydroxyl group, and the formation of the corresponding aldehyde.
The stereochemistry of the product is relevant in this reaction. The addition of BH3 to the triple bond of 1-butyne can occur in two ways, leading to the formation of two different regioisomers. In one regioisomer, the boron atom adds to the terminal carbon of the triple bond, while in the other, it adds to the internal carbon. The reaction is highly regioselective, with the terminal addition being favored. The addition of H2O2 and OH- to the alkenylborane intermediate is also stereoselective, with syn addition being favored. Therefore, the major product of the reaction is (Z)-1-butanal, with the hydroxyl group and the double bond on the same side of the molecule.
In case no reaction occurs, the product is ethane (CH3CH3), which is obtained by the reduction of BH3 with H2O2 and OH-.

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To cool her 0. 200-kg cup of 75. 0°C hot chocolate (mostly water), Heidi drops a 0. 0300-kg cold water at 1. 0°C into her insulated foam cup. The specific heat of water is 4. 184 J/g°C. What is the temperature of the hot chocolate after equilibrium is reached?

Answers

The final temperature of the hot chocolate after equilibrium is reached is 71.1°C.  We used the principle of conservation of energy to find the final temperature of hot chocolate. The heat lost by the hot chocolate will be equal to the heat gained by the cold water.

To find the temperature of the hot chocolate after equilibrium, we can use the principle of conservation of energy. The heat lost by the hot chocolate will be equal to the heat gained by the cold water.

First, let's calculate the heat lost by the hot chocolate. The specific heat capacity of water is given as 4.184 J/g°C, so the heat lost by the hot chocolate can be calculated as:

Q_hot_chocolate = mass_hot_chocolate * specific_heat_water * (initial_temperature_hot_chocolate - final_temperature)

Q_hot_chocolate = 0.200 kg * 4.184 J/g°C * (75.0°C - final_temperature)

Similarly, let's calculate the heat gained by the cold water. The heat gained by the cold water can be calculated as:

Q_cold_water = mass_cold_water * specific_heat_water * (final_temperature - initial_temperature_cold_water)

Q_cold_water = 0.0300 kg * 4.184 J/g°C * (final_temperature - 1.0°C)

According to the principle of conservation of energy, Q_hot_chocolate = Q_cold_water. So we can equate the two equations:

0.200 * 4.184 * (75.0 - final_temperature) = 0.0300 * 4.184 * (final_temperature - 1.0)

Now, solve this equation to find the final temperature of the hot chocolate. After solving, we find that the final temperature of the hot chocolate after equilibrium is reached is approximately 71.1°C.

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