61.

A current of 12 ampere is passed through an electrolytic cell containing aqueous NiSO₄ solution. Both Ni and H₂ gas are formed at the cathode. The current efficiency is 60%. What is the mass of nickel deposited on the cathode per hour?

• 7.883g

• 3.941g

• 5.91g

• 2.645g

The cell reaction of a cell is $\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right) \to \mathrm{Cu}\left(\mathrm{s}\right) + {\mathrm{Mg}}^{2+}\left(\mathrm{aq}\right).$ If the standard reduction potentials of Mg and Cu are - 2.37 and + 0.34V respectively. The emf of the cell is

• 2.03V

• -2.03V

• +2.71V

• -2.71V

In the electrochemical reaction, $2{\mathrm{Fe}}^{3+}+ \mathrm{Zn} \to {\mathrm{Zn}}^{2+}+ 2{\mathrm{Fe}}^{2+}$ increasing the concentration of Fe²⁺

• increases cell emf

• increases the current flow

• decrease the cell emf

• alter the pH of the solution

Aluminium is obtained by

• reducing Al₂O₃ with coke

• electrolysing Al₂O₃ dissolved in Na₃AlF₆

• reducing Al₂O₃ with chromium

• heating alumina with cryolite

What are the products obtained when ammonia is reacted with excess chlorine ?

• N₂ and NCl₃

• N₂ and HCl

• N₂ and NH₄Cl

• NCl₃, and HCl

Reaction of HNO₃ with I, S, P and C gives respectively

• HIO₃, H₂SO₄, H₃PO₄, and CO₂

• HIO₃, H₂SO₃, H₃PO₄, and CO₂

• HIO₂,H₂SO₄, H₃PO₄, and CO

• I₂O₅, SO₂, P₂O, and CO₂

Dry bleach is done by

• O₃

• H₂O₂

• Cl₂

• SO₂

The formation of colloid from suspension is

• peptisation

• condensation

• fragmentation

• sedimentation

Which of the following has maximum value of flocculating power ?

• Pb²⁺

• Pb⁴⁺

• Sr²⁺

• Na⁺

Red P can be obtained by white P by

• Heating it with a catalyst, in an inert atmosphere

• Distilling it in an inert atmosphere

• Dissolving it in CS₂ and crystallizing

• Melting it and pouring the liquid into water