Answer:
7,052.6secs
Explanation:
n of Cu = +2
R.A.M of Cu = 64g
m = 7.25g
I = 3.1A
F = 96500
nF = R.A.M
It = m
2*96500 = 64
3.1*t = 7.25
1,399,250 = 198.4t
t = 7,052.6secs
A sheet of aluminum foil weighs 2.07g. If the sheet is 24cm long and 20cm wide, how thick is the sheet in micrometers? The density of aluminum is 2.7 g/cm3.
Answer:
[tex]h=1.60\mu m[/tex]
Explanation:
Hello,
In this case, given the density and the mass of the aluminum foil, we can compute the occupied volume as shown below:
[tex]\rho =\frac{m}{V}\\ \\V=\frac{m}{\rho}=\frac{2.07g}{2.7g/cm^3} =0.767cm^3[/tex]
Next, since the volume is defined as:
[tex]V=24cm*20cm*h[/tex]
Whereas [tex]h[/tex] accounts for its thickness, we can find it to be:
[tex]h=\frac{V}{24cm*20cm}=\frac{0.767cm^3}{20cm*24cm}\\ \\h=1.60x10^{-3}cm*\frac{10000\mu m}{1cm} \\\\h=1.60\mu m[/tex]
Regards.
how many moles of MgO are produced when .250 mol of Mg reacts completely with O2
Answer:
0.250 moles of MgO are produced when 0.250 mol of Mg reacts completely with O₂
Explanation:
In first place, the balanced reaction between Mg and O₂ is:
2 Mg + O₂ ⇒ 2 MgO
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reactants and products participate in the reaction:
Mg: 2 molesO₂: 1 moleMgO: 2 molesThen you can apply the following rule of three: if by reaction stoichiometry 2 moles of Mg produce 2 moles of MgO, 0.250 moles of Mg, how many moles of MgO will they form?
[tex]moles of MgO=\frac{0.250 moles of Mg*2 moles of MgO}{2 moles of Mg}[/tex]
moles of MgO= 0.250
0.250 moles of MgO are produced when 0.250 mol of Mg reacts completely with O₂
The following equilibrium is formed when copper and bromide ions are placed in a solution:
heat + Cu(H2O)6 ^+2 (blue) + 4Br- <--> 6H2O + CuBr4^-2 (green)
A) answer the following questions when KBr is added to the solution:
1. What will happen to the equilibrium?
2. What will be the color of the solution?
3. Will the solution be hotter or cooler? Explain.
B) What will be the color of the solution when the solution is heated?
Answer:
A)
1. Reaction will shift rightwards towards the products.
2. It will turn green.
3. The solution will be cooler..
B) It will turn green.
Explanation:
Hello,
In this case, for the stated equilibrium:
[tex]heat + Cu(H_2O)_6 ^{+2} (blue) + 4Br^- \rightleftharpoons 6H_2O + CuBr_4^{-2} (green)[/tex]
In such a way, by thinking out the Le Chatelier's principle, we can answer to each question:
A)
1. If potassium bromide, which adds bromide ions, is added more reactant is being added to the solution, therefore, the reaction will shift rightwards towards the products.
2. The formation of the green complex is favored, therefore, it will turn green.
3. The solution will be cooler as heat is converted into "cold" in order to reestablish equilibrium.
B) In this case, as the heat is a reactant, if more heat is added, more products will be formed, which implies that it will turn green.
Regards.
What determines an atom's identity? Question 1 options: Atomic Mass Element Name Number of Protons Number of Neutrons
how does matter form different types of mixtures?
Answer:
pure substances and mixtures
Explanation:
pure substances are further broken down into elements and compound....... A mixture is composed of different types of atoms or molecules that are not chemically bonded.
Heterogeneous and homogeneous mixtures are the two types of mixtures. While homogeneous mixtures seem consistent throughout, heterogeneous mixtures have clearly discernible components. A solution, which can be a solid, liquid, or gas, is the most typical kind of homogenous mixture.
Explain about the types of mixtures?
Mixtures are materials made up of two or more different types of matter. Physical means can be used to separate them. Examples include a salt-water solution, a sugar-water solution, various gases, air, etc. The many components of any mixture do not come together by any sort of chemical transformation.
Solutions, suspensions, and colloids are the three categories into which mixtures can be divided based on particle size. A mixture's constituent parts maintain their unique physical characteristics
Answer:
both pure materials and mixes
Explanation:
The breakdown of pure substances into their component components and compounds continues. Different kinds of unchemically linked atoms or molecules make up a mixture.
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What is the density of an object with a mass of 145.8g and an volume of 91.75 mL?
Answer:
Density = 1.6 g/mLExplanation:
Density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
From the question
mass = 145.8 g
volume = 91.75 mL
Substitute the values into the above formula and solve for the Density
That's
[tex]Density = \frac{145.8}{91.75} [/tex]
= 1.5891
We have the final answer as
Density = 1.6 g/mL
Hope this helps you
What family on the periodic table has ad least one solid, one liquid and one gas.
Answer:
FLUORINE, CHLORINE, BROMINE, IODINE, ASTATILE AND TENNESINE
Explanation :
Florine and chorine=gas
Bromine=liquid
ASTATILE and TENNESINE =solid
HOPE IT is right
The number of possible monobromination products, including cis-trans isomers, of methylcyclopentane is:________
A) 2
B) 3
C) 4
D) 5
E) 6
Answer:
D) 5
Explanation:
In this case, the "monobromination" is the addition of one "Br" to the molecule. With this in mind, we have to explore each option to put this "Br" atom:
1) (bromomethyl)cyclopentane = The Br atom is placed in carbon 6
2) 1-bromo-1-methylcyclopentane = The Br atom is placed in carbon 1
3) (1R,2R)-1-bromo-2-methylcyclopentane = The Br atom is placed in carbon 2 (with trans configuration)
4) (1R,2S)-1-bromo-2-methylcyclopentane = The Br atom is placed in carbon 2 (with cis configuration)
5) 1-bromo-3-methylcyclopentane = The Br atom is placed in carbon 3
See figure 1
I hope it helps!
Decide which element probably has a melting point most and least similar to the melting point of cesium
The question is incomplete, so the complete question is as follows:
Decide which element probably has a melting point most and least similar to the melting point of cesium. Comparing melting point: helium thallium sodium strontium
Answer:
Most similar melting point : Sodium
Least similar melting point: Strontium
Explanation:
Melting point is defined as the temperature at which soid will melt or get converted into liquid.
Melting point of cesium is 28.44 °C and most similar melting point is sodium as its melting point is 97.72°C and least similar melting point is strontium as it has melting point 777°C.
Hence, the correct answer is:
Most similar melting point : Sodium
Least similar melting point: Strontium
consider a 1000-ml graduated cylinder with marks every 100 ml. a student records the volume of liquid in the cylinder as 750 ml. is this the correct measurement? explain
Answer:
Yes, given statement is true.
Explanation:
Given that a cylinder of 1000 ml is marked at every 100 ml.
During the test, the student can easily check the volume of liquid so the student's guess is 750 ml true.
With this measurement, we can estimate that 1/10th of 100 ml can be measured.
So, given statement is correct.
Answer:
Yes, the digit in the hundreds place is certain and the digit in the tens place is estimated.
Explanation:
Heavy nuclides with too few neutrons to be in the band of stability are most likely to decay by what mode?
Answer:
Positron emission
Explanation:
Positron emission involves the conversion of a proton to a neutron. This process increases the mass number of the daughter nucleus by 1 while its atomic number remains the same. The new neutron increases the number of neutrons present in the daughter nucleus hence the process increases the N/P ratio.
A positron is usually ejected in the process together with an anti-neutrino to balance the spins.
The specific heat of aluminum is 0.0215 cal/g°C. If a 4.55 g sample of aluminum absorbs 2.55 cal of energy, by how much will the temperature of the sample change?
Answer:
The change in temperature is [tex]26.06^{\circ} C[/tex].
Explanation:
It is given that,
The specific heat of Aluminium is cal/g°C
Mass of the sample, m = 4.55 g
Heat absorbed, Q = 2.55 cal
We need to find the change in temperature of the sample. The heat absorbed by an object is given by :
[tex]Q=mc\Delta T[/tex]
[tex]\Delta T[/tex] is the change in temperature
So,
[tex]\Delta T=\dfrac{Q}{mc}\\\\\Delta T=\dfrac{2.55\ cal}{4.55\ g\times 0.0215 \ cal/g^{\circ} C}\\\\\Delta T=26.06^{\circ} C[/tex]
So, the change in temperature is [tex]26.06^{\circ} C[/tex].
What type of matter is pepperoni pizza
Answer:
Heterogeneous Mixture. Have a good day! =)
Explanation:
list any five items that can be found in a Science portfolio
Answer:
physical projects
Journal entries
Materials
Lab reports
Artworks
Explanation:
Definition of a Portfolio:
Portfolio can be defined as a physical collection of student work that includes materials such as written assignments, completed tests, artwork, lab reports, physical projects and other material evidence of learning progress and academic accomplishment, including awards and honors,
A portfolio is a long-term form of self reflection and assessment that students do together.
Portfolios are a great way to demonstrate the competencies you would list on a resume or talk about in a science interview
What is the final pH of a solution obtained by mixing 300 ml of 0.4 M NH3 with 175 ml of 0.3 M HCl? (Kb = 1.8 x 10-5) Show all of your math steps. Do not leave us guessing as to how you got your final answer.
Answer:
pH of the final solution = 9.15
Explanation:
Equation of the reaction: HCl + NH₃ ----> NH₄Cl
Number of moles of NH₃ = molarity * volume (L)
= 0.4 M * (300/1000) * 1 L = 0.12 moles
Number of moles of HCl = molarity * volume (L)
= 0.3 M * (175/1000) * 1 L = 0.0525 moles
Since all he acid is used up in the reaction, number of moles of acid used up equals number of moles of NH₄Cl produced
Number moles of NH₄Cl produced = 0.0525 moles
Number of moles of base left unreacted = 0.12 - 0.0525 = 0.0675
pOH = pKb + log([salt]/[base])
pKb = -logKb
pOH = -log (1.8 * 10⁻⁵) + log (0.0525/0.06755)
pOh = 4.744 + 0.109
pOH = 4.853
pH = 14 - pOH
pH = 14 - 4.853
pH = 9.15
Therefore, pH of the final solution = 9.15
The following compounds have similar molecular weights. Which has the highest boiling point?
A. CH3OCH3
B. C2H5OH
C. CH3CH2CH3
D. CH3CH=O
Answer:
[tex]\Huge \boxed{\mathrm{C_2H_5OH}}[/tex]
Explanation:
CH₃OCH₃ (Dimethyl ether) has a boiling point of -23 °C
C₂H₅OH (Ethanol) has a boiling point of 78.37 °C
CH₃CH₂CH₃ (Propane) has a boiling point of -42 °C
CH₃CHO (Acetaldehyde) has a boiling point of 20.2 °C
C₂H₅OH (Ethanol) has the highest boiling point.
Is solar radiation a natural force or a human effect?
Answer:
i think its natural . it is the natural process
Answer:
Solar radiation falls into the category of natural forces.
Explanation:
Natural forces don’t have a strong effect on recent global temperatures. The natural forces line begins to drop around 1950 and does not track with the observed temperature line. On the other hand, the human effects line rises upward with the observed temperatures, so it’s a stronger effect.
Brainilest?
hen solid NH4NO3 is dissolved in water, the temperature of the water and beaker gets noticeably colder. The formation of an aqueous solution of ammonium nitrate is __________
Answer:
The formation of an aqueous solution of ammonium nitrate is An endothermic process
Explanation:
An exothermic process produce energy when occurs. As there is energy that is released, the temperature of the arounds increases.
In the other hand, an endothermic process absorb energy when occurs doing the temperature of the around colder than the initial temperature.
As the dissolution of NH₄NO₃ in water make the temperature of the water colder:
The formation of an aqueous solution of ammonium nitrate is An endothermic processThe formation of an aqueous solution of ammonium nitrate is an endothermic process
The question requires us to determine if reaction process is an endothermic or an exothermic reaction.
To do this,
First we will define the terms Endothermic reaction and exothermic reaction
Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products. These reactions lower the temperature of their surrounding area, thereby creating a cooling effect. They have a net positive standard enthalpy change.
Exothermic reactions are reactions or processes that release energy, usually in the form of heat or light. They have a net negative standard enthalpy change.
From the question,
When solid NH4NO3 is dissolved in water, the temperature of the water and beaker gets noticeably colder. This means it is an endothermic reaction.
Hence, the formation of an aqueous solution of ammonium nitrate is an endothermic process
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Calculate the solubility of BaCO3 (a) in pure water and (b) in a solution in which [CO32-] = 0.289 M. Solubility in pure water = M Solubility in 0.289 M CO32- = M
Answer:
the solubility of BaCO₃ in pure water and in a solution is 4.472 × 10⁻⁵ M and 6.9204 × 10⁻⁹ M respectively.
Explanation:
To calculate the solubility of BaCO₃ in:
(a) pure water and (b) in a solution in which [CO₃²⁻] = 0.289 M
The [tex]ksp[/tex] (i.e solubility constant ) for BaCO₃= 2.0 × 10⁻⁹
BaCO₃ → Ba²⁺ + CO₃²⁻
ksp = s × s
s² = ksp
s = [tex]\sqrt{ksp}[/tex]
s = [tex]\sqrt{2.0 \times 10^{-9}}[/tex]
s = 4.472 × 10⁻⁵ M
(b) The solubility of BaCO₃ in a solution in which [CO₃²⁻] = 0.289 M
BaCO₃ → Ba²⁺ + CO₃²⁻
ksp = s × s
2.0 × 10⁻⁹ = s × 0.289
s = 2.0 × 10⁻⁹/0.289
s = 6.9204 × 10⁻⁹ M
Thus, the solubility of BaCO₃ in pure water and in a solution is 4.472 × 10⁻⁵ M and 6.9204 × 10⁻⁹ M respectively.
Which of the following definitions best describes the term "vapor pressure?a. Pressure and temperature values on a phase diagram where two phases of a substance coexist. b. In equilibrium with the liquid phase, the pressure exerted by a gas. c. Aspecific temperature and pressure at which the liquid and gas phases of a substance have the same density and are indistinguishable from each other. d. The temperature and pressure at which all three phases of a substance coexist. Under these conditions, freezing and melting, boiling and liquefaction, and sublimation and deposition all proceed at the same rate. e. The temperature at which the vapor pressure of a liquid equals 1 atm.
Answer:
b. In equilibrium with the liquid phase, the pressure exerted by a gas.
Explanation:
When a liquid is warmed up to a temperature , it starts vaporising . The liquid is turning into gas and gas is turning into liquid at different rates . Initially the rate of former is higher but gradually the difference of rate between them decreases to zero . At this point the rate of conversion of liquid into gas and rate of conversion of gas into liquid becomes equal . This is called dynamic equilibrium point .
If we change the temperature , the equilibrium gets disturbed .
At this point the pressure exerted by the gas is called the vapour pressure of the liquid .
So option b ) is correct .
At the equilibrium point, the pressure exerted by the gas molecules to the liquid molecules has been termed the Vapor pressure. Thus, statement b is correct.
The vaporization has been the process of conversion of liquid to the gaseous state with the rise in temperature. The liquids attaining a certain temperature have been vaporized into the gaseous state.
Initially, the gas phase has been less in concentration, thus the rate of formation of gas has been greater.
After a certain amount of time, the gas phase starts to cool down and converts to the liquid state. The rate of formation of the liquid has been slower.
The time when the rate of formation of liquid, and the rate of formation of gas has been equal is termed as the equilibrium point. At the equilibrium point, the pressure exerted by the gas molecules to the liquid molecules has been termed the Vapor pressure.
Thus, statement b is correct.
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The percent by mass of methanol (MM = 32.04 g/mol) in an aqueous solution is 21.1%. What is the molality of the methanol solution?
Answer:
Molality of the methanol solution = 8.33 m
Explanation:
Given:
Mass % = 21.1 %
Molar mass of methanol = 32.04 g / mol
Find:
Molality of the methanol solution?
Computation:
Moles of methanol = Mass / Molar mass
Moles of methanol = = 21.1 / 32.04
Moles of methanol = 0.658
Assume.
Mass of solution = 100 g
Mass of solvent = 100 -21.1 = 78.9 g = 0.0789 kg
Molality of the methanol solution = 0.658 / 0.0789
Molality of the methanol solution = 8.33 m
Given values:
Mass percentage = 21.1%Methanol's molar mass = 32.04 g/molNow,
Moles of methanol:
= [tex]\frac{Mass}{Molar \ mass}[/tex]
= [tex]\frac{21.1}{31.04}[/tex]
= [tex]0.658[/tex]
then,
Mass of solution:
= [tex]100-21.1[/tex]
= [tex]78.9 \ g \ or \ 0.0789 \ kg[/tex]
hence,
The molality will be:
= [tex]\frac{0.658}{0.0789}[/tex]
= [tex]8.33 \ m[/tex]
Thus the answer above is correct.
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A scientist wants to use a model to help present the results of his detailed scientific investigation.
Why would a model be useful?
because the model makes the concepts easier to understand
because the model is easy to put together and to use
because the model prevents other scientists from asking questions
Obecause the model requires the audience to pay full attention to it
Answer:
Because the model makes the concepts easier to understand
Explanation:
Models are created to give a visual of every aspect of an experiment. This allows for a better understanding across the board for everyone.
How many milliliters of a 1M nitric acid solution are required to prepare 60mL of 6.7M solution?
A) 400 mL
B) 4mL
C) 0.25 mL
D) none of the above
Answer:
the number of milliliters of a 1M is 402mL
Explanation:
The computation of the number of milliliters could be determined by using the following formula
As we know that
[tex]V_1\times M_1 = V_2\times M_2[/tex]
where,
V_1 and V_2 are the starting and final volumes
And, the M_1 and M_2 are the starting and the final molarities
Now the V_1 is
[tex]V_1 \times 1M = 60mL \times 6.7M[/tex]
So, the V_1 is 402mL
Hence, the number of milliliters of a 1M is 402mL
What is the density of an object with a mass of 83 g and a volume of 34 mL?
Type your answer with at least 2 decimal places.
The mass of a solid substance is 21.112 g. If the volume of the solid substance is 19.5 cm3, calculate the density of the substance (in g/cm3) with the correct number of significant digits. The density is g/cm3.
Answer:
ρ = 1.08 g/cm³
Explanation:
Step 1: Given data
Mass of the substance (m): 21.112 g
Volume of the substance (V): 19.5 cm³
Step 2: Calculate the density of the substance
The density (ρ) of a substance is equal to its mass divided by its volume.
ρ = m / V
ρ = 21.112 g / 19.5 cm³
ρ = 1.08 g/cm³
The density of the substance is 1.08 g/cm³.
Calculate the pZn of a solution prepared by mixing 25.0 mL of 0.0100 M EDTA with 50.0 mL of 0.00500 M Zn2 . Assume that both the Zn2 and EDTA solutions are buffered with 0.100 M NH3 and 0.176 M NH4Cl.
Answer:
[tex]\mathbf{pZn ^{2+} =8.8569 }[/tex]
Explanation:
Using the approach of Henderson-HasselBalch equation, we have :
[tex]pH = pKa[NH^+_4] + log \dfrac{[NH_3]}{[NH_4^+]}[/tex]
where;
the pKa of [tex]NH^+_4[/tex] = 9.26
concentration of [tex]NH_3[/tex] = 0.100 M
concentration of [tex]NH_4Cl[/tex] = 0.176 M
∴
the pH of the buffered solution is :
[tex]pH = 9.26 + log \dfrac{[0.100]}{[0.176]}[/tex]
[tex]pH = 9.26 + log (0.5682)[/tex]
[tex]pH = 9.26 +(-0.2455)[/tex]
[tex]pH =9.02[/tex]
The Chemical equation for the reaction of [tex]Zn ^{2+}[/tex] and EDTA is :
[tex]Zn^{2+}_{(aq)} + Y^{4-}_{(aq)} \iff ZnY^{2-} _{(aq)}[/tex]
Here;
[tex]Y^{4-}_{(aq)}[/tex] denotes the fully deprotonated form of the EDTA
The formation constant [tex]K_f[/tex] of the equation for the reaction can be represented as:
[tex]K_f = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ][Y^{4-}]}[/tex] ----- (1)
The logarithm of the formation constant of Zn - EDTA complex = 16.5
[tex]K_f[/tex] = [tex]10^{16.5}[/tex]
[tex]K_f[/tex] = [tex]3.16 \times 10^{16}[/tex]
Since the formation constant in the above equation signifies that the EDTA is present in [tex]Y^{4-}[/tex],
Then:
[tex]\alpha _{Y^{4-} }= \dfrac{Y^{4-}}{C_{EDTA}}[/tex]
[tex]{Y^{4-}}= \alpha_ {Y^{4-}} \times {C_{EDTA}}[/tex]
From (1)
[tex]K_f = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ][Y^{4-}]}[/tex]
[tex]K_f = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ] \ \ \alpha_ {Y^{4-}} \times {C_{EDTA}}}[/tex]
∴
[tex]K_f' = K_f \times \alpha _Y{^4-} = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ] \ C_{EDTA} }[/tex]
where;
[tex]K_f'[/tex] = conditional formation constant
[tex]\alpha _Y{^4-}[/tex] = the fraction of EDTA that exit in the form of the presences of the 4 charges .
So at equivalence point :
all the [tex]Zn^{2+}[/tex] initially in titrand is now present in [tex]ZnY^{2-}[/tex]
[tex]K_f' = K_f \times \alpha _Y{^4-}[/tex]
Obtaining the data for the value of [tex]\alpha _Y{^4-}[/tex] at the reference table:
[tex]\alpha _Y{^4-}[/tex] = [tex]5.4 \times 10^{-12}[/tex]
∴
[tex]K_f' = 3.16 \times 10^{16} \times 5.4 \times 10^{-2}[/tex]
[tex]K_f' = 1.7064 \times 10^{15}[/tex]
To calculate the moles of EDTA ,[tex]Zn^{2+}[/tex] , [tex]ZnY^{2-}[/tex] ; we have:
moles of EDTA = 0.0100 M × 0.025 L
moles of EDTA = [tex]2.5 \times 10^{-4} \ mole[/tex]
moles of [tex]Zn^{2+}[/tex] = 0.00500 M × 0.050 L
moles of [tex]Zn^{2+}[/tex] = [tex]2.5 \times 10^{-4} \ mole[/tex]
moles of [tex]ZnY^{2-}[/tex] = [tex]\dfrac{initial \ mole}{total \ volume}[/tex]
moles of [tex]ZnY^{2-}[/tex] = [tex]\dfrac{2.5 \times 10^{-4}}{ 0.025 + 0.050 }[/tex]
moles of [tex]ZnY^{2-}[/tex] = [tex]\dfrac{2.5 \times 10^{-4}}{ 0.075 }[/tex]
moles of [tex]ZnY^{2-}[/tex] = 0.0033333 M
Recall that:
[tex]K_f' = K_f \times \alpha _Y{^4-} = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ] \ C_{EDTA} }[/tex]
[tex]K_f' = \dfrac{[ZnY^{2-}]}{[Zn^{2+} ] \ C_{EDTA} }[/tex]
Assume Q² is the amount of complex dissociated in [tex]ZnY^{2-}[/tex]
[tex]ZnY^{2-} \iff Zn^{2+} + C_{EDTA}[/tex]
i.e [tex]Q^2 = Zn^{2+} + C_{EDTA}[/tex]
[tex]1.707 \times 10^{15}= \dfrac{0.0033333}{Q}[/tex]
[tex]Q= \dfrac{0.0033333}{1.707 \times 10^{15}}[/tex]
[tex]Q^2= \dfrac{0.0033333}{1.707 \times 10^{15}}[/tex]
[tex]Q^2= 1.9527 \times 10^{-18}[/tex]
[tex]Q= \sqrt{1.9527 \times 10^{-18}}[/tex]
Q = [tex]1.397 \times 10^{-9}[/tex] M
[tex][Zn^{2+}]= 1.39 \times 10^{-9} \ M[/tex]
∴
[tex]pZn ^{2+} =- log [Zn^{2+}][/tex]
[tex]pZn ^{2+} = - log (1.39 \times 10^{-9} ) \ M[/tex]
[tex]\mathbf{pZn ^{2+} =8.8569 }[/tex]
40.002 g : 13.000005 g =
which of the following changes are chemical changes?
A water if frozen
B water is heated up
C gasoline is burned
D water is boiled
E gasoline is evaporated
Answer:
the answer is C.
Explanation:
this is because burning anything is going to change the make-up of the object
Which one of the following statements a about scientific hypothesis is FALSE? A scientific hypothesis is an educated guess about why something happens. In order to be useful, a scientific hypothesis must be testable in a way that is replicable by other scientists. The previously known outcome of an observation or experiment can be used as solid proof that a newly-created scientific hypothesis is absolutely true. A scientific hypothesis is an explanation for a natural phenomenon.
Answer:
C). The previously known outcome of an observation or experiment can be used as solid proof that a newly-created scientific hypothesis is absolutely true.
Explanation:
A Scientific hypothesis is characterized as the proposed explanation or an educated guess about a natural phenomenon on the basis of previous knowledge as well as observation. All the given statements are true regarding a scientific hypothesis that it is 'an educated guess which explains the reason why a specific phenomenon occurs', 'being testable in a manner that could be replicated by other', 'an explanation for a natural phenomenon' except for that the 'truth of a scientific hypothesis can never be assured completely with a solid proof as it always has chances of being expanded.' Thus, option C is the correct answer.
The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely oxidized by an aqueous solution of BrO3–(aq). Complete and balance the equation for this reaction in acidic solution.
6H+ +Bro3- +3Sb3+----------> Br- +3Sb5+3H2O
Answer:
3Sb^3+(aq) + BrO3^-(aq) + 6H^+(aq)----->3Sb^5+(aq) + Br^-(aq) 3H2O(l)
Explanation:
When we want to balance redox reaction equations, we must ensure that the number of electrons lost in the oxidation half reaction equation is equal to the number of electrons gained in the reduction half reaction equation.
After we have done this, we can now write the overall balanced reaction equation without including the number of electrons lost or gained. Hence;
Oxidation half equation;
3Sb^3+(aq) -----> 3Sb^5+(aq) +6e
Reduction half equation;
BrO3^-(aq) + 6H^+(aq) + 6e ----> Br^-(aq) 3H2O(l)
Overall balanced reaction equation;
3Sb^3+(aq) + BrO3^-(aq) + 6H^+(aq)----->3Sb^5+(aq) + Br^-(aq) 3H2O(l)