Faraday's Second Law

Q.

How many Faradays of electricity are required to deposit $10g$ of calcium from Calcium Chloride (${\mathrm{CaCl}}_2$) using inert electrodes? (Molar mass of Calcium= $40gmo{l}^{-1}$)

Q. N2 + 3H2 = 2NH3 in above reaction equivalent weight of NH3 and H2 are 1) M÷3, M÷3 2) M÷2, M÷3 3)M÷3, M÷3 4)M÷2, M÷

Q. ntsulphuric acid used in a lead storage batteryis 38%by mass and has a density of 1.30g/cm3. calculate its molarity.n

Q. A direct current deposits $54g$ of silver during electrolysis. How much amount of aluminium would be deposited from aluminium chloride solution by the same amount of electricity?
( $\text{Atomic mass of Ag}=108g/mol$)
($\text{Atomic mass of Al}=27g/mol$)

1. $4.5g$
2. $5.4g$
3. $54g$
4. $2.7g$

Q.

Magnesium cation has polarising power close to that of

1. Li⁺

2. Na⁺

3. K⁺

4. Cs⁺

Q. Molten $AlC{l}_3$ is electrolysed using platinum electrode with the current of $0.5$ ampere to produced $27g\text{of}Al$. Find the number of faradays used for deposition of $Al$.

1. 5
2. 3
3. 4
4. 6

Q. $4.5g$ of aluminum (at. mass 27amu) is deposited at cathode from $A{l}^{3+}$ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from $H+$ ions in solution by the same quantity of electric charge will be

1. 22.4 L
2. 44.8 L
3. 5.6 L
4. 11.2 L

Q. Calculate the number of coulombs required to deposit $5.4g$ of Aluminium when the given electrode reaction is
$A{l}^{3+}+3e^{-}\to Al$

1. $60500C$
2. $57900C$
3. $1.83\times {10}^{5}C$
4. $5.86\times {10}^{5}C$

Q. A semiconductor becomes an insulator at

1. $0^{\circ }C$
2. $300K$
3. $-{100}^{\circ }C$
4. $0K$

Q.

When 9.65 coulombs of electricity is passed through a solution of silver nitrate

(atomic weight of taking as 108) the amount of silver deposited is

[EAMCET 1992; KCET 2000]

1. 10.8 mg
2. 5.4 mg
3. 16.2 mg
4. 21.2 mg

Q. equivalent weight of h2so4 in the reaction h2so4---------h2s

Q.

The atomic weight of Al is 27. When a current of 5 Faradays is passed through a solution of Al⁺³ions, the weight of Al deposited is

1. 27 gm

2. 36 gm

3. 45 gm

4. 39 gm

Q. Which of the following statements is not true?
$M{g}^{2+}\left(aq\right)+2e^{-}\to Mg\left(s\right);E^0=-2.36V$
$C{u}^{2+}\left(aq\right)+2e^{-}\to Cu\left(s\right);E^0=0.34V$

1. $MgS{O}_4$ can be stored in $Cu$ vessel
2. $C{u}^{2+}$ has higher oxidising power than $M{g}^{2+}$
3. $Mg$ will reduce $CuS{O}_4$
4. $Cu$ displaces $Mg$ from $MgS{O}_4$

Q. Which of the following is true regarding electrical conductivity of metals and semiconductors?

1. On increasing the temperature, electrical conductivity of metals decreases, while that of semiconductor increases.
2. Electrical conductivity of both metals and semiconductors increases on increasing temperature.
3. On increasing the temperature, electrical conductivity of metals increases, while that of semiconductor decreases.
4. Electrical conductivity of both metals and semiconductors decreases on increasing temperature.

Q.

In a fuel cell, H2& O2 react to produce electricity. In the process, H2 gas is oxidized at the anode & O2 at the cathode . If 67.2 litre of H2 at STP react in 15 minutes, If the entire current is used for electrode deposition of Cu from Cu (II) solution, how many grams of Cu will be deposited?

1. 190.5 g

2. 160 g

3. 280 g

4. 320 g

Q. A semiconductor becomes an insulator at

1. $300K$
2. $0K$
3. $-{100}^{\circ }C$
4. $0^{\circ }C$

Q. The conductivity of a semiconductor can be increased by:

1. Doping the semiconductor with electron rich impurity
2. All of the above
3. Heating the semiconductor
4. Doping the semiconductor with electron deficient impurity

Q. Which of the following is true regarding electrical conductivity of metals and semiconductors?

1. On increasing the temperature, electrical conductivity of metals increases, while that of semiconductor decreases.
2. Electrical conductivity of both metals and semiconductors decreases on increasing temperature.
3. Electrical conductivity of both metals and semiconductors increases on increasing temperature.
4. On increasing the temperature, electrical conductivity of metals decreases, while that of semiconductor increases.

Q.

A certain current liberated 0.504 gm of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution

1. 12.7 gm

2. 15.9 gm

3. 31.8 gm

4. 63.5 gm

Q. A quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline arising $50\%$ current efficiency is:

1. 1158000C
2. 579000C
3. 231600C
4. 289500C

Q.

What current strength would be required to produce hydrogen gas at the rate of $1.12c{m}^3{s}^{-1}$(STP) by the electrolysis of aqueous NaCl solution with 96.5% current efficiency ?

1. 9.65 A

2. 9.31 A

3. 10.00 A

4. 0.10 A

Q. Which of the following statements is not true?
$M{g}^{2+}\left(aq\right)+2e^{-}\to Mg\left(s\right);E^0=-2.36V$
$C{u}^{2+}\left(aq\right)+2e^{-}\to Cu\left(s\right);E^0=0.34V$

1. $Mg$ will reduce $CuS{O}_4$
2. $Cu$ displaces $Mg$ from $MgS{O}_4$
3. $C{u}^{2+}$ has higher oxidising power than $M{g}^{2+}$
4. $MgS{O}_4$ can be stored in $Cu$ vessel

Q.

By passing a certain amount of charge through NaCl solution, 9.2 litre of Cl2 were liberated at S.T.P. When the same charge is passed through a nitrate solution of metal M, 7.467 g of the metal was deposited. If the specific heat of metal is 0.216 cal/g, what is formula of metal nitrate ?

1. MNO₃

2. M(NO₃)₂

3. M(NO₃)₃

4. M(NO₃)₄

Q. Which of the following statement is correct reagarding electrical conductivity of a semiconductor:

1. Increases with the rise in temperature
2. First increases and then decreases with the rise in its temperature
3. Does not change with the rise in its temperature
4. Decreases with the rise in temperature

Q. On passing one faraday of electricity through the electrolytic cells containing $A{g}^{+},N{i}^{+2}$ and $C{r}^{+3}$ ions solution, the deposited $Ag(At.wt.=108),Ni(At.wt.=59)andCr(At.wt.=52)$ is

$\begin{array}{cccc}& Ag\left(ingm\right)& Ni\left(ingm\right)& Cr\left(ingm\right)\\ a)& 108& 59& 52\\ b)& 108& 29.5& 17.3\\ c)& 36& 19.6& 17.3\\ d)& 108& 108& 108\end{array}$

1. a
2. b
3. c
4. d

Q.

Same quantity of electricity is being used to liberate iodine (at anode) and a metal x (at cathode). The mass of x deposited is 0.6 g and the iodine is completely reduced by 50 cc of 0.1M sodium thiosulphate. Find the equivalent mass of x.

1. 120

2. 80

3. 68

4. 20