Question

Platinised asbestos is used as a catalyst in the manufacture of:

• A. $\mathrm{HCl}$
• B. ${\mathrm{H}}_2{\mathrm{SO}}_4$
• C. ${\mathrm{HNO}}_3$
• D. None of the above

Answer 1

The correct option is B

${\mathrm{H}}_2{\mathrm{SO}}_4$

The explanation for Correct answer:

Option (B) ${\mathrm{H}}_2{\mathrm{SO}}_4$

Step 1 Sulphur trioxide is formed:

The contact process is a method to produce concentrated Sulphuric acid which is required for industrial use.

The Sulphur dioxide and Oxygen are combined at a ratio of $1:1$ inside a Lead chamber and the temperature is set to $400–450°\mathrm{C}$ with $1-2\mathrm{atm}.$

$\underset{\mathrm{Sulfur}\mathrm{dioxide}}{2{\mathrm{SO}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\rightleftharpoons \underset{\mathrm{Sulfur}\mathrm{trioxide}}{{\mathrm{SO}}_3\left(\mathrm{g}\right)}$

Platinized asbestos or ${\mathrm{V}}_2{\mathrm{O}}_5$ can be used as a catalyst for this process.

Step 2 Oleum is formed:

The Sulphur trioxide in Sulphuric acid produces oleum.

$\underset{\mathrm{Sulphur}\mathrm{trioxide}}{{\mathrm{SO}}_3\left(\mathrm{g}\right)}+\underset{\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4}⟶\underset{\mathrm{oleum}}{{\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7}$

Step 3 Sulphuric acid is formed:

The Oleum is then diluted in water to produce concentrated Sulphuric acid.

$\underset{\mathrm{Oleum}}{{\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_7\left(\mathrm{l}\right)}+\underset{\mathrm{Cruel}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}⟶\underset{\mathrm{Sulphuric}\mathrm{acid}}{2{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{l}\right)}$

Hence, correct option (B) ${\mathrm{H}}_2{\mathrm{SO}}_4$ is correct.