Question

Consider the following two reactions A and B:

The numerical value of [molar mass of $x$ + molar mass of $y$] is ___. 
 

• A. $46$
• B. $88$
• C. $160$
• D. $4$

Hint:

Acids react with sodium to give $\mathrm{H_2}$, while carboxylic acids react with bicarbonates to release $\mathrm{CO_2}$.

Answer 1

The Correct Option is A

To solve the given problem, we need to identify the gases \(x\) and \(y\) produced in the reactions and then calculate their molar masses.

1. Reaction A: Phenol reacting with Sodium (Na)
   • Phenol (C₆H₅OH) reacts with Sodium (Na) to produce sodium phenoxide and hydrogen gas.
   • Equation: C₆H₅OH + Na → C₆H₅ONa + H₂↑
   • Here, the gas \(x\) is hydrogen (H₂).
   • Molar mass of H₂ = 2 g/mol.
2. Reaction B: Benzoic acid reacting with Sodium bicarbonate (NaHCO₃)
   • Benzoic acid (C₆H₅COOH) reacts with Sodium bicarbonate (NaHCO₃) to produce sodium benzoate, water, and carbon dioxide gas.
   • Equation: C₆H₅COOH + NaHCO₃ → C₆H₅COONa + H₂O + CO₂↑
   • Here, the gas \(y\) is carbon dioxide (CO₂).
   • Molar mass of CO₂ = 44 g/mol.

Adding the molar masses of \(x\) and \(y\):

\(2 \, \text{g/mol} \, (\text{H}_2) + 44 \, \text{g/mol} \, (\text{CO}_2) = 46 \, \text{g/mol}\).

Hence, the numerical value of [molar mass of \(x\) + molar mass of \(y\)] is 46.