Electrochemistry Test

Result

Electrochemistry Test - 31

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

If $$m$$ is the mass of silver deposited at the cathode by $$2 A$$ current flowing for $$25 min$$ through a silver voltameter, then the mass deposited by $$1.5 A$$ current flowing for $$600 s$$ is _________.

A
$$m$$

B
$$3m$$

C
$$0.3m$$

D
None

Solution

$$\displaystyle \frac {{m}'}{m} = \frac {{I}'{t}'}{It} = \frac {1.5 \times 600}{2 \times 25 \times 60} = \frac {900}{3000} = \frac {3}{10} = 0.3$$

$$\Rightarrow {m}'=0.3m$$
Question 2
1 / -0

The liberation of $$1$$ mole of chlorine requires how many Faradays of electricity?

A
$$0.5$$ Faraday

B
$$0.25$$ Faraday

C
$$2$$ Faradays

D
$$4$$ Faradays

Solution

$$2Cl^- \rightarrow Cl_2 + 2e^-$$
$$Q={n(e^-)}\times {F}$$
2mol electrons are liberated in production of 1mol of chlorine.
therefore electricity required for the process
$$\Rightarrow$$ $$= {2}\times {F}$$ = $$2$$ Faradays
Question 3
1 / -0

A voltaic cell is represented as $${A}_{(s)}\left| { { A }^{ +2 } }_{ (aq) } \right| \left| { { B }^{ +2 } }_{ (aq) } \right| {B}_{(s)}$$. Which of the following statements of false regarding the above cell?

A
The double vertical line indicates salt bridge

B
$$A$$ is called the anode and $$B$$ is called the cathode

C
The cell reactions are represented as $${A}^{2+}+2{e}^{-}\rightarrow A$$ and $$B\rightarrow {B}^{2+}+2{e}^{-}$$.

D
None of the above

Solution

Cell diagram is represented as
$$\underset{Anode} {A_{(s)}}\left| \underset {Oxidation}{{ A }^{ +2 }}_{ (aq) } \right| \left| \underset{Cathode} {{ B }^{ +2 }_{ (aq)}} \right| \underset {Reduction}{B}_{(s)}$$.
The cell reactions are represented as $${A}\rightarrow {A}^{+2} + 2e^-$$ and $$B^{+2} + 2e^-\rightarrow {B}$$
Question 4
1 / -0

In an electrolyte, $$3.2 \times 10^{18}$$ bivalent positive ions drift to the right per second while $$3.6 \times 10^{18}$$ monovalent negative ions drift to the left per second. The current through the electrolyte is _______.

A
$$0.45 A$$ to the left

B
$$0.45 A$$ to the right

C
$$1.6 A$$ to the right

D
$$1.6 A$$ to the left

Solution

Current $$I =$$ net charge transported/second
$$= 3.2 \times 10^{18} \times 2e + 3.6 \times 10^{18} \times e$$
$$= (6.u + 3.6) \times 10^{18} \times 1.6 \times 10^{-19}$$
$$= 10 \times 1.6 \times 10^{-1}$$
$$= 1.6 A$$ to the right.
Question 5
1 / -0

Lead pipes are readily corroded by:

A
water

B
acetic acid

C
conc. $$H_2SO_4$$

D
dil. $$H_2SO_4$$

Solution

Corrosion of lead is strongly accelerated by traces of acetic acid. Acetic acid in the presence of oxygen rapidly attacks lead and produces very soluble lead(II) acetate which precludes the use of lead to process or store wine or fruit juice.
Question 6
1 / -0

If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of:

A
$$CuCO_3$$

B
$$CuSO_4$$

C
$$CuCO_3.Cu(OH)_2$$

D
$$CuO$$

Solution

Copper reacts with $$CO_2$$ present in the air and forms a green coating on its surface due to the formation of basic copper carbonate.

$$2Cu+O_2+CO_2+H_2O\rightarrow CuCO_3.Cu(OH)_2$$

So, the correct option is $$C$$
Question 7
1 / -0

According to the electrochemical concept, corrosion occurs at :

A
anodic area of metal

B
cathodic area of metal

C
both cathodic and anodic areas of metal

D
neither cathodic area nor anodic areas of metal

Solution

Corrosion can be defined as the deterioration of materials by chemical processes.
Of these, the most important by far is electrochemical corrosion of metals in which the oxidation process $$M \rightarrow M^+ + e^-$$ is facilitated by the presence of a suitable electron acceptor. This is possible because metals are conductive and so, the electrons can flow through the metal from the anodic to the cathodic regions.
Metallic corrosion occurs when metal atoms are oxidized and subsequently leave the metal lattice as ions. The oxidation reaction of the metal is referred to as the anodic half-reaction. The areas on a metal surface where oxidation occurs are referred to as anodes.

Option A is correct.
Question 8
1 / -0

As dilution of the solution increases then the conductivity of solution ___________.

A
increases

B
decreases

C
remain unchanged

D
none of the above

Solution

The conductivity of a weak electrolyte increases with an increase dilution. As the dilution increases the number of ion increases and they get free from their co-ions and can move independently from each other. So by increasing dilution the rate of conductivity increases as more ions are available for conductance
Question 9
1 / -0

The hydrogen formed by the action of zinc on sulphuric acid forms a layer of gas on the surface of copper plate in a simple voltaic cell, because of which

A
Internal resistance of the cell increases

B
Hydrogen ions are unable to reach the anode

C
Polarisation takes place at the anode

D
All of the above

Solution

The hydrogen formed by the action of zinc on sulphuric acid forms a layer of gas on the surface of a copper plate in a simple voltaic cell, because of which:-
$$\rightarrow$$ Internal resistance of cell increases
$$\rightarrow$$ Hydrogen ions are unable to reach the anode
$$\rightarrow$$ polarisation takes place at an anode.
Question 10
1 / -0

When a corroded metal object is rubbed by a sand paper then:

A
outer metal surface is removed

B
metal becomes thin

C
outer corroded layer will be removed

D
all of the above

Solution

The metals lose their shine and become dull when exposed to air for a long time. Due to the formation of oxides, when the surface is rubbed by a sand paper, then the outer corroded layer is removed.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Electrochemistry Test - 31

Result

Electrochemistry Test - 31

Score

-

Rank

-

SHARING IS CARING

Question 1

$$m$$

$$3m$$

$$0.3m$$

None

Solution

Question 2

$$0.5$$ Faraday

$$0.25$$ Faraday

$$2$$ Faradays

$$4$$ Faradays

Solution

Question 3

The double vertical line indicates salt bridge

$$A$$ is called the anode and $$B$$ is called the cathode

The cell reactions are represented as $${A}^{2+}+2{e}^{-}\rightarrow A$$ and $$B\rightarrow {B}^{2+}+2{e}^{-}$$.

None of the above

Solution

Question 4

$$0.45 A$$ to the left

$$0.45 A$$ to the right

$$1.6 A$$ to the right

$$1.6 A$$ to the left

Solution

Question 5

water

acetic acid

conc. $$H_2SO_4$$

dil. $$H_2SO_4$$

Solution

Question 6

$$CuCO_3$$

$$CuSO_4$$

$$CuCO_3.Cu(OH)_2$$

$$CuO$$

Solution

Question 7

anodic area of metal

cathodic area of metal

both cathodic and anodic areas of metal

neither cathodic area nor anodic areas of metal

Solution

Question 8

increases

decreases

remain unchanged

none of the above

Solution

Question 9

Internal resistance of the cell increases

Hydrogen ions are unable to reach the anode

Polarisation takes place at the anode

All of the above

Solution

Question 10

outer metal surface is removed

metal becomes thin

outer corroded layer will be removed

all of the above

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.