Electrolysis and Electrolytes

Q. How long (approximate) should water be electrolysed by passing through 100 amperes of current so that the oxygen released can completely burn 27.66 g of diborane? (atomic weight of borane 10.8 u)

1. 0.8 hours
2. 3.2 hours
3. 6.4 hours
4. 1.6 hours

Q. What is the Conjugate acid of NH2^-

Q.

When a lead storage battery is discharged, then:

Q. An electric current of $100$ ampere is passed through a molten liquid of sodium chloride between platinum electrodes for 5 hours. Calculate the volume of chlorine gas liberated at the electrode at NTP.
[Molar mass of $C{l}_2$ is $71g/mol$]

1. $209L$
2. $420.7L$
3. $22.4L$
4. $310L$

Q.

What happens when voltage is increased during electrolysis?

Q. The anodic half-cell of lead-acid battery is recharged using electricity of 0.05 Faraday. The amount of $PbS{O}_4$ electrolysed in g during the process is:(molar mass of $PbS{O}_4$=303 g ${\mathrm{mol}}^{-1}$)

1. 22.8
2. 15.2
3. 7.6
4. 11.4

Q. 67 pH of 0.1M BOH (weak base) is found to be 12. The solution at temperature T K will display an osmotic pressure equal to _______ (a) 0.01RT (b) 0.01(RT) (c) 0.11RT (d) 1.1RT

Q.

The first order rate constant for the decomposition of N₂O₅ is 6.2 x 10^-4 sec^-1. The t_1/2 of the decomposition reaction is

1. 228.4 sec

2. 168.9 sec

3. 1117.7 sec

4. 111.7 sec

Q.

Identify the incorrect statement from the options below for the given cell:

1. If E_ext = 1.1 V, no flow of e– or current occurs

2. If E_ext > 1.1 V, Zn dissolves at the Zn electrode and Cu deposits at the Cu electrode

3. If E_ext > 1.1 V, e^- flow from Cu to Zn

4. If E_ext < 1.1 V, Zn dissolves at the anode and Cu deposits at the cathode

Q.

What is the difference between strong and weak electrolytes?

Q. pH of 0.1 M CH3COOH solution is 3 at 25 degree celcius . if limiting molar conductivity of CH3COO- and H+ are 40 and 350 S cm2 mol-. the molar conductance at 25 degree for 0.1M CH3COOH

Q.

During the electrolysis of water, one Faraday of charge would liberate

1. 22.4 lit. of oxygen

2. One mole of oxygen

3. One gram atom of oxygen

4. 8g of oxygen

Q. Conductance measurements can be used to detect the end point of acid-base titrations. Which of the following plots correctly represent the end point of the titration of monobasic strong acid and a monoacidic strong base?

1. 
2. 
3. 
4. 

Q.

The osmotic pressure of a solution of $\mathrm{NaCl}\mathrm{is}0.10\mathrm{atm}$ and that of a glucose solution is $0.20\mathrm{atm}$. The osmotic pressure of a solution formed by mixing $1\mathrm{L}$ of the sodium chloride solution with $2\mathrm{L}$ of the glucose solution is $\mathrm{x}\times {10}^{-3}\mathrm{atm}$. $\mathrm{x}$ is

Q.

Which is more conducive acid or base?

Q.

What is Weston cadmium cell ?

Q.

A trivalent metallic oxide contains $68.4\%$ by weight of metal. What could be the atomic weight of the metal?

(a) 27

(b) 39

(c) 52

(d) 152

1. $27$

2. $39$

3. $52$

4. $152$

Q.

The limiting molar conductivity for KCl, NaBr and NaCl are 100, 120, 130 S cm^-2mol^-1 respectively. Calculate the limiting molar conductivity for KBr?

1. 110 S cm^-2mol^-1

2. 350 S cm^-2mol^-1

3. 90 S cm^-2mol^-1

4. 210 S cm^-2mol^-1

Q.

The time required to remove electrolytically one fourth of Ag from 0.2 L of 0.1 M AgNO₃solution by a current of 0.1 ampere is approximately:

1. 40 min

2. 320 min

3. 160 min

4. 80 min

Q. During electrolysis of $CuS{O}_4$, using $Pt$-electrodes, the $pH$ of solution

1. Increases
2. Decreases
3. Remains unchanged
4. Can’t be predicted

Q. In electrolysis of water:

Q.

A certain salt X, gives the following results.

(i) Its aqueous solution is alkaline to litmus.

(ii) It swells up to a glassy material Y on strong heating.

(iii)When conc. $H_{2}S{O}_4$ is added to a hot solution of X, white crystal of an acid Z separates out.

Write equations for all the above reactions and identify X, Y and Z.

Q.

What Is Normal Diode?

Q. How JJ Thomson found the charge by mass ratio?

Q.

Write the equations for the reaction taking place at the cathode and at the anode during:

The electrolysis of acidified Nickel sulphate solution with NIckel electrode.

Q.

Describe the industrial preparation of Hydrogen by the electrolysis of water.

Q.

If the standard hydrogen electrode acts as a cathode, the reaction at cathode will be:

1. H⁺ (aq) + e^-→ H₂ (g)

2. 2H⁺ (aq) + 2e^-→ H₂ (g)

3. H₂ (g) → H⁺ (aq) + e^-

4. H₂ (g) → 2H⁺ (aq) + 2e^-

Q.

How does the addition of electrolytes cause coagulation?

Q. Which of the following statement is true for ionic solids ?

1. Under the electric field, cations and anions acquire translatory motion in opposite directions
2. Structural units have strong electrostatic force of attraction
3. Structural units have dipole-dipole interactions
4. Ionic solids are soluble in non-polar solvent

Q. The approximate time duration in hours to electroplate $30g$ of calcium from molten calcium chloride using a current of $5A$ is (Atomic mass of $Ca=40g/mol$)

1. 80
2. 10
3. 16
4. 8