Calculate the pH of the cathode compartment solution if the cell emf at 298 K is measured to be 0.660 V when (Zn^2+)=0.22 M and(P_H2)= 0.87atm.

Answers

Answer 1

Answer:

pH = 2.059

Explanation:

At the Cathode:

The reduction reaction is:

[tex]2H^+ + 2e^- \to H_2 \ \ \ \mathbf{E^0_{red}= 0.00 \ V}[/tex]

At the anode:

At oxidation reaction is:

[tex]Zn \to Zn^{2+} +2e^- \ \ \ \mathbf{E^0_{ox} = 0.76 \ V}[/tex]

The overall equation for the reaction is:

[tex]\mathbf{Zn + 2H^+ \to Zn^{2+} + H_2}[/tex]

The overall cell potential is:

[tex]\mathbf{E^0_{cell}= E^0_{ox} + E^0_{red}}[/tex]

[tex]\mathbf{E^0_{cell}= 0.76 \ V +0.00 \ V}[/tex]

[tex]\mathbf{E^0_{cell}= 0.76\ V}[/tex]

Using the formula for the Nernst equation:

[tex]E = E^0 - ( \dfrac{0.0591}{n})log (Q)\\[/tex]

where;

E = 0.66

(Zn^2+)=0.22 M

Then

[tex]0.66 =0.76- ( \dfrac{0.0591}{2})log \bigg ( \dfrac{[Zn^{2+} ] PH_2}{[H^+]^2} \bigg )[/tex]

[tex]0.66 =0.76- 0.02955 * log \bigg ( \dfrac{0.22*0.87}{[H^+]^2} \bigg )[/tex]

3.4 = log ( 0.1914) - 2 log [H⁺]

3.4 = -0.7180 - 2 log [H⁺]

3.4 + 0.7180 = - 2 log  [H⁺]

4.118  = - 2  log  [H⁺]

pH = log [H⁺] = 4.118/2

pH = 2.059

Answer 2

The pH of the solution as described in the question is 2.7.

The equation of the reaction is;

Zn(s) + 2H^+(aq) ----> Zn^2+(aq) + H2(g)

The partial pressure of hydrogen can be converted to molarity using;

P= MRT

M = P/RT

M =  0.87atm/0.082 LatmK-1mol-1 × 298 K = 0.036 mol/L

We have to obtain the reaction quotient

Q = [Zn^2+] [H2]/[H^+]^2

Q = [0.22 ] [0.036]/[H^+]^2

Recall that, from Nernst equation;

E = E° - 0.0592/nlog Q

E° = 0.00V - (-0.76V) = 0.76V

0.660 =  0.76 - 0.0592/2logQ

0.660 - 0.76  =  - 0.0592/2logQ

-0.1 =  - 0.0592/2logQ

-0.1 × 2/ - 0.0592 = logQ

3.38 = log Q

Q = Antilog (3.38)

Q= 2.39 × 10^3

Now;

2.39 × 10^3 =  [0.22 ] [0.036]/[H^+]^2

2.39 × 10^3 = 7.92  × 10^-3/[H^+]^2

[H^+]^2 = 7.92  × 10^-3/2.39 × 10^3

[H^+] = 1.82  × 10^-3

pH = -log[H^+]

pH = -log[ 1.82  × 10^-3]

pH = 2.7

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Related Questions

Which is the largest number? O A. 2.2 x 108 O B. 2.9 O C. 2.5 x 10-5 D. 2.8 x 106​

Answers

Answer:

2.2 x 10⁸

Explanation:

We are to find the largest number from the given set of numbers:

      2.2 x 10⁸

      2.9

      2.5 x 10⁻⁵

      2.8 x 10⁶

The largest number is the first one;  2.2 x 10⁸ ;

  2.2 x 100 000 000

the other numbers are far lesser than this number;

   

Give the name for the molecular compound O3Cl2.​

Answers

Answer:

dichlorine trioxide

Explanation:

di-2 tri-3 there are three oxygens and two chlorines.

Answer:

Dichlorine Trioxide

Explanation:

The molar mass and molecular weight of Cl2O3 is 118.904.

If an ideal gas has a pressure of 5.87 atm,
a temperature of 26.86 ∘C,
and a volume of 77.31 L,
how many moles of gas are in the sample?

Answers

Answer:

5.87/26.86=77.31/...

Explanation:

after solving this u can find the answer in easy way

Please help me it’s due today at 6:00pm please help me please please

Answers

Answer:

a) an opposing force act on it

i hope its true

HELP ME PLEASE I will mark brainliest

Answers

Answer:

Nice pic there

Explanation:

No need

Each pure substance has characteristic physical and chemical properties that can be used to identify it.

Compare and contrast physical properties and chemical properties of a substance. Give and example for each:

Answers

Stuff like color, and density are examples of physical properties. Flammability and corrosion/oxidation are examples of chemical properties

among the intermolecular forces,which forces are typically the weakest

Answers

Answer:

The London dispersion force is the weakest intermolecular force. The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.

The Lanthanides are often be found below the Periodic Table so it will fit nicely on a textbook page. If they were inserted into the Periodic Table, where would they go?

group 7
group 6
period 7
period 6

Answers

Answer:

period 6

Explanation:

If the lanthanides were inserted into the periodic table, they would go into periodic 6.

Their atomic number is between 57 - 71 from element lanthanum to lutetium.

The elements in this period are 15 in number. They are also know as elements in the f-block.

The elements that makes up the series are:

Lanthanum

Cerium

Praseodymium

Neodymium

Promethium

Samarium

Europium

Gadolinium

Terbium

Dysprosium

Holmium

Erbium

Thulium

Ytterbium

Lutetium

What property of gases confirms that the space between the particles of gas is significantly larger than when the same substance is in a liquid state?
A. Mobility
B. Reactivity
C. Volatility
D. Compressibility​

Answers

The answer is D. Compressibility

Answer:

D. Compressibility​

Explanation:

according to the law of energy conservation, the total amount of energy is constant, then why does the chemical energy in electric cells got used up?

Answers

Answer:

The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.

Explanation:

This means that a system always has the same amount of energy unless it's added from the outside. is the total internal energy of a system.

What bond distance is expected to be longest?
1. A carbon-carbon bond with a bond order of 2
2. A carbon-carbon bond with a bond order of 3
3. A carbon-carbon bond with a bond order of O
4. carbon-carbon bond with a bond order of 1​

Answers

Answer:

Bond length of C=C is largest(134 pm) because both the carbon atoms have same electronegativity. In case of C=O. and C=N carbon is bonded to highly electronegative atoms so bond length is shoreter as compared to C=C

The heat of vaporization of acetic acid is . Calculate the change in entropy when of acetic acid condenses at .

Answers

The question is incomplete, the complete question is;

The heat of vaporization ΔHv of acetic acid HCH3CO2 is 41.0 /kJmol. Calculate the change in entropy ΔS when 954.g of acetic acid condenses at 118.1°C. Be sure your answer contains a unit symbol. Round your answer to 3 significant digits.

Answer:

-1.67 JK-1

Explanation:

Since Heat of vaporization of acetic acid = 41.0 kJ/mol

Therefore:

Heat of condensation of acetic acid = -41.0 kJ/mol

Mass of acetic acid = 954 g

Temperature of condensation = 118.1 °C or 391.1 K

Number of moles of acetic acid = 954 g/60g/mol = 15.9 moles

Heat evolved during condensation = 15.9 moles *  -41.0 kJ/mol = -651.9 KJ

Entropy change (ΔS) = Heat evolved/ Temperature = -651.9 KJ/391.1 K

Entropy change (ΔS) = -1.67 JK-1

What is an aqueous solution and what does it do?

Answers

Answer:

An Aqueous solution is used to reference any solution where water acts as the solvent. A lot of substances can dissolve in water including acids and bases and when they do this they become aqueous solutions.

Aqueous solutions are denoted by the symbol (aq) in solutions as shown in this reaction below where Sodium Chloride is dissolved in water;

NaCl(s) → Na+(aq) + Cl-(aq)

Aqueous solutions are capable of conducting electricity if electrolytes are the ones dissolved in the water.

There are however some substances that cannot form aqueous solutions because they cannot dissolve well in water for example, organic substances like oils.

Which is produced in a synthesis reaction?
A) a single element
B) single compound
C) single ion
D) single atom

Answers

Answer:

A single compound is produced in a synthesis reaction.

Explanation:

What are chemical reactions?

Chemical reactions are when two or more reactants chemically react with one another to create one or more substances as products. There are five types: synthesis, decomposition, single-replacement, double-replacement, and combustion.

Types of Reactions and Examples of Each

A synthesis reaction takes two or more reactants and reacts chemically to turn them all into one substance.

An example of a synthesis reaction is the reaction that takes place between sodium (Na) and chlorine (Cl) to create table salt.This reaction would be displayed as [tex]{\text{Na} + \text{Cl} \rightarrow \text{NaCl}}.[/tex]The parent reaction for a synthesis reaction is [tex]\text{A} + \text{B} \rightarrow \text{AB}.[/tex]

A decomposition reaction takes one reactant and breaks itself into two or more products.

An example of a decomposition reaction would be the decomposition of hydrogen (H₂) and oxygen (O) to create two diatomic molecules - H₂ + O₂. This reaction would be displayed as [tex]\text{H}_{2}\text{O} \rightarrow \text{H}_{2} + \text{O}_{2}.[/tex]The parent reaction for a decomposition reaction is [tex]\text{AB} \rightarrow \text{A} + \text{B}[/tex].

A single-replacement reaction takes place when two compounds chemically combine but one of the elements bonds with a different element.

An example of a single-replacement reaction would be the single-replacement of calcium and water to create calcium hydroxide and dihydrogen.This reaction would be displayed as [tex]\text{Ca} + \text{H}_{2} \text{O} \rightarrow \text{CaO} + \text{H}_{2}.[/tex]The parent reaction for a single-replacement reaction is [tex]\text{A} + \text{BX} \rightarrow \text{AX} + \text{B}.[/tex]

A double-replacement reaction works in the same way as a single-replacement reaction - however, instead of one replacement, there are two replacements.

An example of a double-replacement reaction would be the double-replacement of sodium bicarbonate (baking soda) and vinegar to produce carbonic acid and sodium acetate.This reaction would be displayed as [tex]\text{NaHCO}_{3} + \text{HC}_{2} \text{H}_{3} \text{O}_{2} \rightarrow \text{NaC}_{2} \text{H}_{3} \text{O}_{2} + \text{H}_{2} \text{O} + \text{CO}_{2}.[/tex]The parent reaction for a double-replacement reaction is [tex]\text{AX} + \text{BY} \rightarrow \text{AY} + \text{BX}.[/tex]

A combustion reaction is the introduction of heat or energy and oxygen to decompose reactants into carbon dioxide and water.

An example of a combustion reaction would be the burning of propane in a grill.This reaction would be displayed as [tex]\text{C}_{3} \text{H}_{8} + \text{5O}_{2} \rightarrow \text{3CO}_2 + \text{4H}_2 \text{O}.[/tex]The parent reaction for a combustion reaction is [tex]\text{Hydrocarbon} + \text{O} \rightarrow \text{CO}_2 + \text{H}_2 \text{O}.[/tex] A hydrocarbon is a substance that is only hydrogen and carbon.

Therefore, based on the above information, we can determine that a single compound, or option B, is the product of a synthesis reaction.

Answer:

single compound

Explanation:

A synthesis reaction will take more than two reactants. It will chemically mix together and then it forms a synthesis reaction. The elements involved are single compounds.

Our answer is single compounds.

Sean plated an unknown metal onto his silver earring which initially weighed 1.41 g. He constructs an electrolytic cell using his ring as one of the electrodes. After running the cell, 0.022 moles of the unknown metal was plated onto his ring and the mass of the ring increased to 3.952 g. What is the atomic weight of the unknown metal in g/mol

Answers

Answer:

115 g/mol

Explanation:

Step 1: Given data

Initial mass of the earring (mi): 1.41 gFinal mass of the earring (mf): 3.952 gMoles of the unknown metal deposited (n): 0.022 mol

Step 2: Calculate the mass of the unknown metal deposited

An earring is plated in an electrolytic cell. The mass of the unknown metal deposited can be calculated using the following expression.

m = mf - mi

m = 3.953 g - 1.41 g

m = 2.54 g

Step 3: Calculate the molar mass (M) of the unknown metal

0.022 moles of the metal have a mass of 2.54 g. The molar mass of the metal is:

M = m/n

M = 2.54 g / 0.022 mol

M = 115 g/mol

How many alkyl substituents does N-ethyl-N-methylaniline have?
one
two
O three
o eight
none

Answers

Answer:

Two.

Explanation:

Hello!

In this case, considering the attached picture wherein you can see the presence of the parent chain as aniline, we can see radicals at the nitrogen, named by N-ethyl and N-methyl which are the present alkyl substituents. In such a way, the benzene ring is not considered an alkyl radical because it belongs to the parent chain on aniline and therefore, N-ethyl-N-methylaniline has two alkyl substituents.

Best regards!

There are two alkyl substituents attached to the nitrogen; one ethyl and one methyl group

Aniline consists of a benzene ring to which an -NH2 moiety is attached. Usually, it is possible for the any of the two hydrogen atoms in the -NH2 moiety to become substituted leading to N-alkylated product.

In the compound N-ethyl-N-methylaniline, there are two alkyl substituents attached to the nitrogen; one ethyl and one methyl group as shown in the image attached to this answer.

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Each molecule of lycopene contains 40 atoms of carbon (plus other atoms). The mass percent of carbon in lycopene is 84.49%. What is the molar mass of lycopene?a. 1137.2 g/mol
b. 405.9 g/mol
c. 480.4 g/mol
d. 473.4 g/mol
e. 568.6 g/mol

Answers

Answer: 568g/mol

Explanation:

It should be noted that there are 40 atoms of carbon in lycopene.

Since mass of 1 carbon = 12g/mol

Mass of 40 carbon atoms = 40 × 12g/mol = 480g/mol

Let the molar mass of lycopene be represented by x.

Therefore the molar mass of carbon = x × mass percent of carbon in lycopene

x × 84.49% = 480g/mol

x × 0.8449 = 480g/mol

x = 480/0.8449

x = 568g/mol

The molar mass of lycopene is 568g/mol

How many moles of dinitrogen monoxide are present in 9.3 x 10^22 molecules of this compound?

Answers

Answer:

0.15 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities.

From the question we have

[tex]n = \frac{9.3 \times {10}^{22} }{6.02 \times {10}^{23} } \\ = 0.154485...[/tex]

We have the final answer as

0.15 moles

Hope this helps you

How many milliliters of a 12-molar HCl must be diluted to obtain 2.0 liters of 3.0-molar HCl?

Answers

Answer: 500ml

Explanation:

Using the Dilution formula that

C₁V₁=C₂V₂

Where

C₁=the molarity of  concentrated solution

= 12 M

V₁ = Volume of the concentrated solution

=?

C₂=the molarity of  the diluted solution

=3.0M

V₂= Volume of the diluted  solution= 2 liters

Changing 2 liters to millilitres  

1000ml= 1 Liters

2Liters=2000ml

Bringing the formulae and inputting the given values

C₁V₁=C₂V₂

12 x V₁= 3.0 x 2000ml

V₁= 3.0 x 2000 / 12

V₁=500ml

Therefore 500ml of 12-molar HCl mst be diluted to obtain 2 Liters of 3.0 Molar HCl.

Draw the structure of the bromohydrin formed when (E)-2-hexene reacts with Br, H20.

Use the wedge hash bond tools to indicate stereochemistry where it exists.

• If the reaction produces a racemic mixture, draw both stereoisomers.

Separate multiple products using the - sign from the drop-down menu.

a

С P

opy to

2

2/10

OOOO. [+

Answers

Answer:

See explanation and image attached

Explanation:

The addition of a halohydrin to an alkene proceeds via the bromium cyclic intermediate.

The bromine dissociates heterolytically and attacks the (E)-2-hexene yielding the brominuim ion intermediate. This is now attacked by water with a consequent loss of H^+ to yield the final product.

Since the reaction involves a flat and planar carbocation intermediate, racemization is possible, thereby leading to the two stereoisomers shown in the image attached to this answer.

3. What is the formula for copper (II) iodide?
Cuz12
Cul2
Cul
Cu21

Answers

Answer

Cu I ( valance number of copper is 2 and valance number of iodide is 1)

so CuI2 so the answer is B.

The answer is B

That’s the answer

What's is the definition of an atom

Answers

Atom, smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic properties of a chemical element. As such, the atom is the basic building block of chemistry.

The tiny particles called atoms are the basic building blocks of all matter. Atoms can be combined with other atoms to form molecules, but they cannot be divided into smaller parts by ordinary means.

The movement of water is able to transport minerals and nutrients. Which statement best explains why water is able to do this?
A. Water has a density of one gram per milliliter
B. Water is an excellent solvent
C. Water absorbs heat energy
D. Water is a liquid at room temperature​

Answers

The correct answer would be B

A 2.4L balloon filled with helium at room temperature 25oC is put into liquid nitrogen
(-196oC). What will the new volume be?

Answers

Answer:

V₂ = 0.62 L

Explanation:

Given data:

Initial volume = 2.4 L

Initial temperature = 25°C

Final temperature = -196°C

Final volume = ?

Solution:

Initial temperature = 25°C (25+273 = 298 K)

Final temperature = -196°C ( -196+273 = 77 K)

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

V₂ = V₁T₂/T₁  

V₂ = 2.4 L × 77 K / 298 k

V₂ = 184.8 L.K / 298 K

V₂ = 0.62 L

If salt water has a density of 1.2 g/mL, which object listed below would SINK? *
Object 1 with a density of 1.14 g/cm3
Object 3 with a density of 1.62 g/cm3
Object 4 with a density of 0.8 g/cm3
Object 2 with a density of 0.92 g/cm3

Answers

what are the objects listed?

For Hydrogen bonding H atom needs to be bonded to which other atoms?

Answers

Answer:

Hydrogen bonding occurs when a hydrogen atom is covalently bonded to N, O, or F atom.

Which element has a smaller atomic radius?
tungsten (74) or oxygen (8)

Answers

Answer:

Oxygen

Explanation:

Atomic radius trend

-decreases from left to right

-increases from top to bottom

Tungsten is in period 7, which has a larger atomic radius

Oxygen is in period 2, which is in a lower energy level and is on the right side. Therefore, has a smaller atomic radius.

A reaction occurs in a calorimeter, resulting in the starting temperature of 38.8 ℃ and final temperature 21.0 ℃. What can you say about the reaction and the enthalpy change (ΔH) during the reaction?

Answers

Answer:

hola comoe stas

Explanation:

gracias x los puntos

Compounds of copper(II) are generally colored, but compounds of copper(I) are usually colorless. Use crystal field theory to explain why this is true.

Answers

Answer:

See explanation

Explanation:

The crystal field theory assumes the interaction between the central metal ion and ligands to be purely electrostatic.

The five d orbitals remain degenerate until they are surrounded by ligands which split the degeneracy of the d orbitals depending on the crystal fields formed to give either square planar, octahedral, tetrahedral or other kinds of crystal fields.

The electronic configuration of Cu II ion is 1s2 2s2 2p6 3s2 3p6 3d9. Its colour arises from an incomplete d orbital which makes d - d electron transition possible.

On the other hand, the electron configuration of copper I is  1s2 2s2 2p6 3s2 3p6 3d10. We can see that the d orbital is completely filled. Hence copper I ion has no color due to its completely filled d- orbitals

Calculate the electrical double layer length for pure water at pH 7. Assume temperature is 300K, and give your answer in units of nm.

Answers

Answer:

[tex]$\lambda_D =964 \ nm$[/tex]

Explanation:

We know, the double layer length of pure water is given by :

[tex]$\lambda _{D}= \left(\frac{\epsilon k_B T}{2e^2z^2N_AC_i}\right)^{1/2}$[/tex]

[tex]$\lambda _{D}= \left(\frac{(78.3)\times(8.85 \times 10^{-21})\times (1.38 \times 10^{-23})\times 300}{2 \times(1.6 \times 10^{19})^2 \times 1^2 \times (6.023 \times 10^{23})\times (10^{-7}) \times 1000 }\right)^{1/2}$[/tex]

Since, pH = -log [tex]$H^+$[/tex]

          [tex]$[H^+]=10^{-7}$[/tex]

[tex]$\lambda_D = \left(93.05 \times 10^_{-14}\right)^{1/2}$[/tex]

[tex]$\lambda_D = \sqrt{93.05} \times 10^{-7}$[/tex]

[tex]$\lambda_D =9.64 \times 10^{-7}$[/tex]

[tex]$\lambda_D =964 \times 10^{-9} \ m$[/tex]

[tex]$\lambda_D =964 \ nm$[/tex]

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