Electrochemistry Test

Question 1
1 / -0

Which one of the following species has maximum conductance in their aqueous solutions?

A
$$K_2PtCl_6$$

B
$$PtCl_4 \cdot 2NH_3$$

C
$$PtCl_4 \cdot 3NH_3$$

D
$$PtCl_4 \cdot 5NH_3$$

Question 2
1 / -0

For the reduction of silver ions will copper metal, the standard cell potential was found to be $$+0.46\ V$$ at $$25^{\circ}C$$. The value of standard gibbs energy, $$\Delta G^{\circ}$$ will be:
$$(F = 96500\ C\ mol^{-1})$$

A
$$89.0\ kJ$$

B
$$-89.0\ kJ$$

C
$$-44.5\ kJ$$

D
$$-98.0\ kJ$$

Question 3
1 / -0

The approximate time duration in hours to electroplate 30 g of calcium from molten calcium chloride using a current of 5 amp is :
[Atomic mass of $$Ca = 40$$]

A
8

B
80

C
10

D
16

Question 4
1 / -0

An electrolysis of a oxytungsten complex ion using $$1.10\ A$$ for $$40$$ min produces $$0.838\ g$$ of tungsten. What is the charge of tungsten in the material? (Atomic weight: $$W = 184$$)

A
$$6$$

B
$$3$$

C
$$5$$

D
$$1$$

Question 5

1 / -0

Consider a galvanic cell using solid $$Cu$$ and $$Fe$$ metals with their corresponding solutions.
What is the $$E^{\circ}_{cell}$$?

Standard Potential (V)	Reduction Half-Reaction
$$2.87$$	$$F_{2}(g) + 2e^{-} \rightarrow 2F^{-}(aq)$$
$$1.51$$	$$MnO_{4}^{-}(aq) + 8H^{+}(aq) + 5e^{-}\rightarrow Mn^{2+}(aq) + 4H_{2}O(l)$$
$$1.36$$	$$Cl_{2}(aq) + 3e^{-} \rightarrow 2Cl^{-}(aq)$$
$$1.33$$	$$Cr_{2}O_{7}^{2-} (aq) + 14H^{+}(aq) + 6e^{-} \rightarrow 2Cr^{3+}(aq) + 7H_{2}O(l)$$
$$1.23$$	$$O_{2}(g) + 4H^{+}(aq) + 4e^{-}\rightarrow 2H_{2}O(l)$$
$$1.06$$	$$Br_{2}(l) + 2e^{-} \rightarrow 2Br^{-}(aq)$$
$$0.96$$	$$NO_{3}^{-}(aq) + 4H^{+}(aq) + 3e^{-}\rightarrow NO(g) + H_{2}O(l)$$
$$0.80$$	$$Ag^{+}(aq) + e^{-} \rightarrow Ag(s)$$$
$$0.77$$	$$Fe^{3+} (aq) + e^{-} \rightarrow Fe^{2+}(aq)$$
$$0.68$$	$$O_{2}(g) + 2H^{+}(aq) + 2e^{-}\rightarrow H_{2}O_{2}(aq)$$
$$0.59$$	$$MnO_{4}^{-}(aq) + 2H_{2}O(l) + 3e^{-}\rightarrow MnO_{2}(s) + 4OH^{-}(aq)$$
$$0.54$$	$$I_{2}(s) + 2e^{-}\rightarrow 2I^{-}(aq)$$
$$0.40$$	$$O_{2}(g) + 2H_{2}O(l) + 4e^{-} \rightarrow 4OH^{-}(aq)$$
$$0.34$$	$$Cu^{2+}(aq) + 2e^{-} \rightarrow Cu(s)$$
$$0$$	$$2H^{+}(aq) + 2e^{-}\rightarrow H_{2}(g)$$
$$-0.28$$	$$Ni^{2+}(aq) + 2e^{-}\rightarrow Ni(s)$$
$$-0.44$$	$$Fe^{2+}(aq) + 2e^{-}\rightarrow Fe(s)$$
$$-0.76$$	$$Zn^{2+}(aq) + 2e^{-}\rightarrow Zn(s)$$
$$-0.83$$	$$2H_{2}O(l) + 2e^{-}\rightarrow H_{2}(g) + 2OH^{-}(aq)$$
$$1.66$$	$$Al^{3+}(aq) + 3e^{-}\rightarrow Al(s)$$
$$-2.71$$	$$Na^{+}(aq) + e^{-} \rightarrow Na(s)$$
$$-3.05$$	$$Li^{+}(aq) + e^{-}\rightarrow Li(s)$$

$$-0.78 V$$

$$0.10 V$$

$$0.78 V$$

$$-0.10 V$$

Question 6
1 / -0

How many coulombs of electricity are required for the oxidation of one mole of water to dioxygen?

A
$$9.65 \times { 10 }^{ 4 }C$$

B
$$1.93 \times { 10 }^{ 4 }C$$

C
$$1.93 \times { 10 }^{ 5 }C$$

D
$$19.3 \times { 10 }^{ 5 }C$$

Question 7
1 / -0

Electrolysis of dilute aqueous NaCl solution was carried out by passing 10 mA current. The time required to liberate 0.01 moles of $$H_2$$ gas at the cathode is

A
$$9.65 \times 10^4 s$$

B
$$19.3 \times 10^4 s$$

C
$$28.95 \times 10^4 s$$

D
$$38.6 \times 10^4 s$$

Question 8
1 / -0

The reaction taking place in the cell $$Pt|\underset {1\ atm}{H_{2}(g)}|HCl(1.0\ M)|AgCl|Ag$$ is:

A
$$AgCl + (1/2)H_{2} \rightarrow Ag + H^{+} + Cl^{-}$$

B
$$Ag + H^{+} + Cl^{-} \rightarrow AgCl + (1/2) H_{2}$$

C
$$2Ag^{+} + H_{2} \rightarrow 2Ag + 2H^{+}$$

D
$$2Ag + 2H^{+} \rightarrow 2Ag^{+} + H_{2}$$

Question 9
1 / -0

The heat of combustion of ethanol in a bomb calorimeter is $$-670.48Kcal\ { mol }^{ -1 }$$ at $${25}^{o}C$$. What is $$\Delta E$$ at $${25}^{o}C$$ for the reaction?

A
-269.24 kcal

B
-469.28 kcal

C
-671.07 kcal

D
+770.48 kcal

Question 10
1 / -0

Consider an electrochemical cell in which the following reaction occurs and predict which changes will decreases the cell voltage:

$$Fe^{2+} (aq) + Ag^{+}(aq)\rightarrow Ag(s) + Fe^{3+}(aq)$$

(I) decreases the $$[Ag^{+}]$$ (II) increases in $$[Fe^{3+}]$$ (III) increase the amount of $$Ag$$

A
I only

B
II and III only

C
II only

D
I and II only

Submit Test

Electrochemistr...

Question 1

$$K_2PtCl_6$$

$$PtCl_4 \cdot 2NH_3$$

$$PtCl_4 \cdot 3NH_3$$

$$PtCl_4 \cdot 5NH_3$$

Question 2

$$89.0\ kJ$$

$$-89.0\ kJ$$

$$-44.5\ kJ$$

$$-98.0\ kJ$$

Question 3

8

80

10

16

Question 4

$$6$$

$$3$$

$$5$$

$$1$$

Question 5

$$-0.78 V$$

$$0.10 V$$

$$0.78 V$$

$$-0.10 V$$

Question 6

$$9.65 \times { 10 }^{ 4 }C$$

$$1.93 \times { 10 }^{ 4 }C$$

$$1.93 \times { 10 }^{ 5 }C$$

$$19.3 \times { 10 }^{ 5 }C$$

Question 7

$$9.65 \times 10^4 s$$

$$19.3 \times 10^4 s$$

$$28.95 \times 10^4 s$$

$$38.6 \times 10^4 s$$

Question 8

$$AgCl + (1/2)H_{2} \rightarrow Ag + H^{+} + Cl^{-}$$

$$Ag + H^{+} + Cl^{-} \rightarrow AgCl + (1/2) H_{2}$$

$$2Ag^{+} + H_{2} \rightarrow 2Ag + 2H^{+}$$

$$2Ag + 2H^{+} \rightarrow 2Ag^{+} + H_{2}$$

Question 9

-269.24 kcal

-469.28 kcal

-671.07 kcal

+770.48 kcal

Question 10

I only

II and III only

II only

I and II only

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