Test: Electrochemistry (November 16) - NEET MCQ

 At anode :

This is because zinc has higher oxidation potential than Ni, Cu and Sn. The process of coating of iron surface with zinc is known as galvanization. Galvanized iron sheets maintain their lustrue due to the formation of protective layer of basic zinc carbonate.

For a concentration cell having different concentrations of ions.

If all the concentrations are identical then obviously the cell voltage is zero. But as the pH of 0.1 M HCl (strong acid) & pH of 0.1M CH₃ COOH is (weak acid) not same, therefore the cell voltage is not zero.

Given molarity = 0.01 M Resistance = 40 ohm;

Cell constant

Specific conductivity (k)

Molar conductance  

In elctrochemical series, Sn is above hydrogen and Hg below hydrogen. Elements above hyrogen are reducing in nature while below hydrogen are oxidising in nature.

With out losing its concentrati on Zn Cl₂ solution can not kept in contact with Al because Al is more reactive than Zn due to electrode (reduction) potential.

Given specific conductance of the solution (k) = 0.012 ohm^–1 cm^–1 and resistance (R) = 55 ohm. We know that cell constant = Specific conductance × Observed resistance = 0.012 × 55= 0.66cm^–1.

For bottom of ship to be protected it is connected with more reactive metal than iron like magnesium. This technique is called cathodic protection.

reaction is not possible because Br^– ion is not oxidised in Br₂ with I₂ due to higher electrode (oxidation) potential of I₂ than bromine.

In electrolysis of NaCl when Pt electrode is taken then H₂ liberated at cathode while with Hg cathode it forms sodium amalgam because more voltage is required to reduce H⁺ at Hg than Pt.z

ΔG = –nEF

For 1 mol of Al, n = 3

According to question, 827 x1000 = 4 x E x 96500

Efficiency of a fuel cell