Answer:
10.10
Explanation:
Step 1: Write the basic dissociation reaction for pyridine
C₅H₅N(aq) + H₂O(l) ⇌ C₅H₅NH⁺(aq) + OH⁻(aq) Kb = 1.9 × 10⁻⁹
Step 2: Calculate [OH⁻]
For a weak base, we will use the following expression.
[OH⁻] = √(Cb × Kb) = √(9.2 × 1.9 × 10⁻⁹) = 1.3 × 10⁻⁴ M
Step 3: Calculate pOH
We will use the definition of pOH.
pOH = -log [OH⁻] = -log 1.3 × 10⁻⁴ = 3.9
Step 4: Calculate pH
We will use the following expression.
pH = 14 - pOH = 14 - 3.9 = 10.10
Given the amount of camphor (200mg) we are using in this experiment, please determine how many mg of sodium borohydride to use in this reaction. We would like you to use 5.2 molar equivalents of this reagent. This means 5.2 times the mmol of camphor we are using. As an example: for 110.0 mg of camphor,142 mg of NaBH4 would be used (see if you can confirm this result). For complete credit, your work needs to be clearly drawn out!
Answer:
Explanation:
From the given information:
Camphor may be reduced as readily in the presence of sodium borohydride(NaHB4). The resulting compound which is stereoselective requires 1 mole of sodium borohydride (NaHB4) to reduce 1 mole of camphor in this reaction. The reaction is shown below.
Through the reduction process of camphor, the reducing agent can reach the carbonyl face with a one-carbon linkage. The product stereoisomer is known as borneol.
If the molecular weight of camphor = 152.24 g/mol
and it mass = 200 mg
The its no of moles = 200 mg/ 152.24 g/mol
= 1.3137 mmol
Now the amount of the required mmol for NaBH4 to be consumed in the reaction = 5.2 × 1.3137 mmol
= 6.831 mmol
since the molar mass of NaBH4 = 37.83 g/mol
Then, using the same formula:
No of moles = mass/molar mass
mass = No of moles × molar mass
mass = 6.831 mmol × 37.83 g/mol
mass of NaBH4 used = 258.42 mg
the force of attraction between non polar molecules are what (a)electrovalent bond (b)covalent bond (c)Hydrogen bond (d)Van der waals forces
Answer:
d. van der waals force
Explanation:
Van der Waals force :
the weakest intermolecular forceand consist of dipole-dipole force and dispersion force.
A sealed container was filled with 0.300mol H2(g), 0.400mol I2(g), and 0.200mol HI(g) at 870K and total pressure 1.00bar. Calculate the amounts of the components in the mixture at equilibrium given that K.= 70 for the reaction H2(g)+I2(g) --> 2HI(g).
Answer:
[HI] = 0.704mol
[H2] = 0.048mol
[I2] = 0.148mol
Explanation:
Based on the equilibrium:
H2(g)+I2(g) --> 2HI(g)
The equilibrium constant, K, is defined as:
K = 70 = [HI]² / [H2] [I2]
Where [] could be taken as the moles in equilibrium of each reactant
To know the direction of the equilibrium we need to find Q with the initial moles of each species:
Q = [0.200mol]² / [0.300mol] [0.400mol]
Q = 0.333
As Q < K, the reaction will shift to the right producing more HI. The equilibrium moles are:
[HI] = 0.200mol + 2X
[H2] = 0.300mol - X
[I2] = 0.400mol - X
Replacing in K:
70 = [0.200 + 2X ]² / [0.300 - X] [0.400 - X]
70 = 0.04 + 0.8 X + 4 X² / 0.12 - 0.7 X + X²
8.4 - 49 X + 70 X² = 0.04 + 0.8 X + 4 X²
8.36 - 49.8X + 66X² = 0
Solving for X:
X = 0.252 moles. Right solution
X = 0.502 moles. False solution. Produce negative moles.
Replacing:
[HI] = 0.200mol + 2*0.252 mol
[H2] = 0.300mol - 0.252 mol
[I2] = 0.400mol - 0.252 mol
[HI] = 0.704mol
[H2] = 0.048mol
[I2] = 0.148mol
Write a chemical equation for KOH(aq) showing how it is an acid or a base according to the Arrhenius definition.
Express your answer as a chemical equation. Identify all of the phases in your answer.
Write a chemical equation for NH4+(aq) showing how it is an acid or a base according to the Arrhenius definition.
Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer:
Write a chemical equation for KOH(aq) showing how it is an acid or a base according to the Arrhenius definition.
Express your answer as a chemical equation. Identify all of the phases in your answer.
Write a chemical equation for NH4+(aq) showing how it is an acid or a base according to the Arrhenius definition.
Express your answer as a chemical equation. Identify all of the phases in your answer.
Explanation:
According to this theory, an acid is a substance that is a proton donor when the substance is dissolved in water.
The base is the one that gives OH- ions when dissolved in water.
KOH(aq) is a base.
Because it releases OH- ions when dissolved in water.
[tex]KOH(aq)->K^+(aq)+OH^-(aq)[/tex]
The ammonium ion is an acid.
It can donate a proton when dissolved in water.
[tex]NH_4^+(aq)->NH_3(aq)+H^+(aq)[/tex]
3)O que são políticas públicas?
Answer:
azertyuiopazertyuiiop
What is the best explanation for why solid sodium chloride CANNOT conduct electricity and why molten sodium chloride can?
Answer: See explanation
Explanation:
The explanation for why solid sodium chloride can't conduct electricity while molten sodium chloride can is explained below:
Ionic compounds that are in their solid state like sodium chloride have their ions fixed in position. Due to this reason, the able to move, therefore we can say that the solid ionic compounds cannot be able to conduct electricity.
On the other hand, ionic compounds in their molten state, are free to flow unlike when they're in their solid state and therefore we can say that molten sodium chloride can be able to conduct electricity.
To identify a halide, you can react a solution with chlorine water in the presence of mineral oil.
If the unknown halide is a
Choose...weaker/stronger
reducing agent than chlorine, the halide will be oxidized to
Choose...its elemental form/ its ionic form/ a solid
which would change the color of the
Choose...mineral oil/ aqueous
layer.
Answer:
- Stronger reducing agent than Chlorine
- Oxidized to it's elemental form
- Change the colour of the aqueous layer.
Explanation:
Halides are electronegative elements in group seven of the Periodic table which have gained electrons to complete their electronic configuration.
They include F-, CL-, Br- and I-.
As you descend the group electro negativity decreases as the number of outermost shells increases. Hence F- is the most electronegative while I- is the least electronegative.
In terms of oxidising and reducing abilities amongst the halogens, since an oxidizing agent readily accepts electrons and is thereby reduced, oxidizing power decreases down the group.
For example, Fluorine being the strongest oxidising agent in the group readily accepts electrons from other members of the group and is reduced to the fluoride ion
F + e = F -
Therefore in terms of oxidizing abilities,
F > Cl > Br > I
Conversely, , as the oxidising power decreases down the group, the reducing powers increases
Therefore, in terms of reducing powers,
I > Br > Cl > F
In the test for halide ions using aqueous chlorine, since chlorine is a stronger oxidizing agent/weaker reducing agent than Bromine or iodine, it readily accepts their electrons forming the chloride ion.
Cl2 + 2 Br- = 2 Cl- + Br2
The bromide ion (assuming the unknown halide is bromide) being a stronger reducing agent/weaker oxidizing agent than Chlorine would readily lose it's electrons and get oxidized to it's elemental form changing the colour of the aqueous layer to brown.
That is : Br2- = Br2 + 2e
The fill in the blanks could be filled with stronger, elemental form and mineral oil.
Identification of a halide:In the case when the halide is not known so it should be stronger. The halide should be oxidized with respect to the elemental form and it should change the color of mineral oil. Due to this, halide should be oxidized for elemental halogen i.e. more soluble for mineral oil.
Learn more about the water here: https://brainly.com/question/21281574
The shape of the sulfur dioxide molecule, where sulfur is the central atom is
bent.
linear.
trigonal planar.
tetrahedral.
Answer:
bent
Explanation:
The molecular formula of sulfur dioxide is written as SO₂
The molecular geometry of sulfur dioxide can be determined using the Lewis structure.
The Lewis structure shows the distribution of electrons around the atoms of a given compound such as sulfur dioxide (SO₂).
In this compound, sulfur is the central atom with 6 valence electrons.
The sulfur is bonded covalently with two oxygen atoms, each with 6 valence electrons. Oxygen contributes 2 lone pairs while sulfur which is the central atom contributes 1 lone pair of electrons in the bond.
The bond angle between the two oxygen atoms and the central sulfur atom is approximately 120⁰, as a result of the bent shape of the molecular structure.
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Answer:
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Explanation:
From the given data it is clear that the unknown compound gives positive test with 2,4-DNP reagent.
That means it has a carbonyl group.Either aldehyde or ketone.
It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test.
That means aldehyde is absent.
So, the other carbonyl group that is ketone is present in the given unknown compound.
Question 9
2 pts
How many milliliters of 1.0 M HCl needs to be diluted to make 200 mL of a 0.1 M solution?
O 0.2 mL
O 0.02 mL
O 20 mL
2 mL
2 nts
Answer: There are 20 milliliters of 1.0 M HCl is required to be diluted to make 200 mL of a 0.1 M solution.
Explanation:
Given: [tex]M_{1}[/tex] = 1.0 M, [tex]V_{1}[/tex] = ?
[tex]M_{2}[/tex] = 0.1 M, [tex]V_{2}[/tex] = 200 mL
Formula used is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute values into the above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\1.0 M \times V_{1} = 0.1 M \times 200 mL\\V_{1} = \frac{0.1 M \times 200 mL}{1.0 M}\\= 20 mL[/tex]
Thus, we can conclude that there are 20 milliliters of 1.0 M HCl is required to be diluted to make 200 mL of a 0.1 M solution.
18. Which of the following solutions will have the highest boiling point?
A. 0.50 mol CH20. in 1.0 kg of water
B. 0.50 mol NaCl in 1.0 kg water
C. 0.50 mol HF in 1.0 kg of water
D. 0.50 mol AICI, in 1.0 kg water
Answer:
highest boiling point.
Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us to recall the definition of colligative properties, more specifically that of boiling point elevation, defined in terms of the temperature change, van't Hoff's factor, molality of the solution and boiling point elevation constant:
[tex]\Delta T_b=i*m*K_b[/tex]
In such a way, since all the given solutions have the same molality and solvent (water), they all have the same m and Kb, for which we focus on the van't Hoff's factor which is 1 for CH2O (nonionizing), 2 for NaCl (Na and Cl ions are released), 2 for HF (H and F ions are released) and 3 for AlCl₃ (one Al and three Cl ions are released).
Therefore, since D. 0.50 mol AICI, in 1.0 kg water has the greatest van't Hoff's factor, we infer it has the highest boiling point.
Regards!
What Is The Name For CH3(CH2)4CH3
Answer:
hexane
I hope it's helps you
Which group has one valence electron
Answer:
Alkaline earth metals or akali metals
Which is a property of all bases?
Answer: The property of all bases is that they are substances which neutralizes an acid to form a salt and water only.
Explanation:
A base is also s substance that can accept or combine with a proton; a proton acceptor.
Bases include the oxides, hydroxides and carbonates of metals. These include MgO,Na2O, NaOH,Ca(OH)2. Most metals burn in oxygen to form metallic oxides which are basic. Examples are the MgO and Na2O.
Other properties or characteristics of bases includes:
--> They have a bitter taste.
--> They turn red litmus paper blue.
--> They are soapy to touch.
--> Aqueous solutions of bases are also electrolytes. Bases can be either strong or weak, just as acids can.
Bases (sodium hydroxide) can be used in the preparation of soaps, glass, paper and rayon. While some bases (magnesium hydroxide) can also be used to manufacture toothpaste and laxatives.
If mass of an empty 9.4 mL pycnometer is 10.3 and the mass of the same pycnometer with an unknown liquid is 20.1. Determine the density of the unknown liquid to the correct number of significant figures in g/mL
Answer:
1.04 g/mL
Explanation:
Applying,
D = (m-m')/V................. Equation 1
Where D = Density of the unknown liquid, m = mass of the pycnometer when filled with unkwon liquid, m' = mass of the empty pycnometer, V = volume of the empty pycnometer
From the question,
Assuming the mass are in grams
Given: m = 20.1 g, m' = 10.3 g, V = 9.4 mL
Substitute these values into equation 1
D = (20.1-10.3)/9.4
D = 9.8/9.4
D = 1.04 g/mL
help with the following would be greatly appreciated!
What is bond energy
atomaticity of chlorine 1) 2, 2)1, 3) 32 , 4) 4.
Answer:
ATOMICITY OF CHLORINE IS 2Explanation:
Atomicity is defined as the total number of atoms present in a molecule.
Combustion of 29.26 gg of a compound containing only carbon, hydrogen, and oxygen produces 33.86 gCO2gCO2 and 13.86 gH2OgH2O. Part A What is the empirical formula of the compound
Answer:
C2H4O3
Explanation:
Empirical formula is defined as the simplest whole number ratio of atoms present in a molecule.
To solve this question we need to find the moles of carbon = Moles of CO2, the moles of hydrogen (Using moles of H2O) and the moles of oxygen (Finding the mass of the mass of each atom) as follows:
Moles Carbon -Molar mass CO2: 44.01g/mol-:
33.86g CO2 * (1mol/44.01g) = 0.769 moles CO2 = Moles C * (12g/mol) =
9.23g C
Moles Hydrogen -Molar mass H2O: 18.01g/mol-
13.86g H2O * (1mol/18.01g) = 0.770 moles H2O * (2mol H / 1mol H2O) = 1.54 moles H * (1g/mol) = 1.54g H
Moles Oxygen:
Mass: 29.26g - 9.23g C - 1.54g H = 18.49g O * (1mol/16g) = 1.156 moles O
Dividing each number of moles in the moles of C (Lowe number of moles):
C = 0.769 moles C / 0.769 moles C = 1
H = 1.54 moles H / 0.769 moles C = 2
O = 1.156 moles O / 0.769 moles C = 1.5
As the number must be a whole number each ratio twice:
C = 2
H = 4
O = 3
Empirical formula is:
C2H4O3C3H8 is ________
A. unsaturated
B. saturated
How do you predict the geometrical shape of NH3 on VSEPR model
Answer:
NH3 Ammonia
Explanation:
Ammonia has 4 regions of electron density around the central nitrogen atom (3 bonds and one lone pair). These are arranged in a tetrahedral shape. The resulting molecular shape is trigonal pyramidal with H-N-H angles of 106.7°.
Consider the arrangement of gases shown below. If the value between the gases is opened and the temperature is held constant, determine the following.
Answer:
I don't know what to say . just for points
Methanol has the formula CH3OH. What is the predominant intermolecular force between methanol molecules?
ANSWER:
dispersion forces
dipole forces
ionic bonds
hydrogen bonds
Answer:
hydrogen bonds
Explanation:
similarly CH3OH also has a OH group and H hydrogen thus it will also form h-bonding.
Increasing the temperature of a chemical reaction usually increases greatly the rate of the reaction. The most iportant reason for this is that increasing the temperature increases: _______.
A) the collision frequency
B) the probability factor
C) the fraction of collisions with energy greater than Bact
D) the energy of activation.
E) the amount of heat released in the reaction
Answer:
the fraction of collisions with energy greater than Eact
Explanation:
The activation energy of a reaction stands as a sort of energy barrier between reactants and products. It is only reactants that possesses energy greater than the activation energy that can be converted from reactants to products.
When the temperature of the system is increased, more particles acquire energy greater than the activation energy. Hence, the fraction of collisions with energy greater than the activation energy increases so the rate of reaction increases likewise.
Assign oxidation state to each atom in each element ion or compound.
a. Ag
b. Ag+
c. CaF2
d. H2S
e.CO3
f. CrO4
g. Cl2
h. Fe
i. CuCl2
j. CH4
Answer:
a. [tex]Ag^0[/tex]
b. [tex]Ag^{+}[/tex]
c. [tex]Ca^{2+}F_2^-[/tex]
d. [tex]H_2^+S^{2-}[/tex]
e. [tex](C^{4+}O_3^{2-})^{-}[/tex]
f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]
g. [tex]Cl_2^0[/tex]
h. [tex]Fe^0[/tex]
i. [tex]Cu^{2+}Cl_2^-[/tex]
j. [tex]C^{4-}H_4^+[/tex]
Explanation:
Hello there!
In this case, according to the concept of charge balance, which tell us that the overall charge is zero for any compound, except ions, it turns out possible to proceed as follows:
a. [tex]Ag^0[/tex]
b. [tex]Ag^{+}[/tex]
c. [tex]Ca^{2+}F_2^-[/tex]
d. [tex]H_2^+S^{2-}[/tex]
e. [tex](C^{4+}O_3^{2-})^{-}[/tex]
f. [tex](Cr^{6+}O_4^{2-})^{2-}[/tex]
g. [tex]Cl_2^0[/tex]
h. [tex]Fe^0[/tex]
i. [tex]Cu^{2+}Cl_2^-[/tex]
j. [tex]C^{4-}H_4^+[/tex]
Keep in mind lonely elements have 0 as their oxidation state.
Regards!
Calculate the mass of water produced when 1.57g of butane reacts with excess oxygen
Explanation:
So, first you will want to write the balanced chemical equation for this reaction.
Butane = [tex]C_4H_{10}[/tex]
[tex]2C_4H_{10}+13O_2=>10H_2O+8CO_2[/tex]
^ This ends up being your balanced chemical equation. Now, you can do the math!
[tex]1.57gC_4H_{10}*\frac{1molC_4H_{10}}{58.12gC_4H_{10}}*\frac{10molH_2O}{2molC_4H_{10}}*\frac{18gH_2O}{1molH_2O}[/tex]
After plugging this into a calculator, your final mass of water should be:
2.43gH2O
What is the cell potential of an electrochemical cell that has the half-reactions shown below?
Ag⁺ + e⁻ → Ag
Fe → Fe³⁺ + 3e⁻
Answer:
E°(Ag⁺/Fe°) = 0.836 volt
Explanation:
3Ag⁺ + 3e⁻ => Ag°; E° = +0.800 volt
Fe° => Fe⁺³ + 3e⁻ ; E° = -0.036 volt
_________________________________
Fe°(s) + 3Ag⁺(aq) => Fe⁺³(aq) + 3Ag°(s) ...
E°(Ag⁺/Fe°) = E°(Ag⁺) - E°(Fe°) = 0.800v - ( -0.036v) = 0.836 volt
At 298 K, AHO = -1652 kJ/mol and ASO = 0.097 kJ/(K•mol). What is the Gibbs
free energy of the reaction?
Based on the calculations, the Gibbs's free energy for this chemical reaction is equal to -1,680.906 kJ/mol.
Given the following data:
Enthalpy of reaction (ΔH°) = -1652 kJ/mol.Temperature = 298 K.Entropy of reaction (ΔS°) = 0.097 kJ/mol.What is Gibbs's free energy?Gibbs's free energy simply refers to the quantity of energy that is associated with a particular chemical reaction.
Mathematically, the Gibbs's free energy for this chemical reaction can be calculated by using this formula:
ΔG° = ΔH° - ΔS°
Substituting the given parameters into the formula, we have;
ΔG° = -1652 × 10³ - (298 × 0.097)
ΔG° = -1652 × 10³ - 28.906
ΔG° = -1,680.906 kJ/mol.
Read more on Gibbs's free energy here: brainly.com/question/18752494
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4. If matter goes through a chemical change, are the physical properties likely to stay the same?
•
Please say yes or no and explain why.
Answer: If matter goes through a chemical change then the physical properties are not likely to stay the same.
Explanation:
When chemical composition of a substance changes during a chemical reaction then it is called a chemical change.
Chemical change always leads to the formation of new substances. Properties like chemical reactivity, combustion, rusting etc are chemical changes.
For example, [tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]
Here, [tex]NH_{3}[/tex] will have different chemical as well as physical properties as compared to [tex]N_{2}[/tex] and [tex]H_{2}[/tex].
As physical properties are the properties that cause change in state of a substance.
Properties like boiling point, state of substance etc are physical properties.
Thus, we can conclude that if matter goes through a chemical change then the physical properties are not likely to stay the same.
When a photon of red light hits metal X, an electron is ejected. Will an electron be ejected if a photon of yellow light hits metal X?
A. Yes
B. No
C. Can't tell