Question

Consider the reaction
\(4\text{HNO}_3(\text{l}) + 3\text{KCl}(\text{s}) \rightarrow \text{Cl}_2(\text{g}) + \text{NOCl}(\text{g}) + 2\text{H}_2\text{O}(\text{g}) + 3\text{KNO}_3(\text{s})\)
The amount of HNO₃ required to produce 110.0 g of KNO₃ is
(Given : Atomic masses of H, O, N and K are 1, 16, 14 and 39 respectively.)

• A. 32.2 g
• B. 69.4 g
• C. 91.5 g
• D. 162.5 g

Answer 1

The Correct Option is C

To determine the amount of \(\text{HNO}_3\) required to produce 110.0 g of \(\text{KNO}_3\), we'll follow these steps:

1. First, calculate the molar mass of \(\text{KNO}_3\). 

Element	Atomic Mass	Number of Atoms	Total Mass
K	39	1	39
N	14	1	14
O	16	3	48
Total Molar Mass of \(\text{KNO}_3\)			101 g/mol

1. Calculate the number of moles of \(\text{KNO}_3\) in 110.0 g.

\(\text{Moles of KNO}_3 = \frac{\text{mass}}{\text{molar mass}} = \frac{110.0 \, \text{g}}{101 \, \text{g/mol}} \approx 1.089 \, \text{mol}\)

1. Use the stoichiometry of the reaction to determine the moles of \(\text{HNO}_3\) required.

According to the balanced chemical equation:

\(4\text{HNO}_3 + 3\text{KCl} \rightarrow \ldots + 3\text{KNO}_3 \\)

3 moles of \(\text{KNO}_3\) require 4 moles of \(\text{HNO}_3\).

\(\text{Moles of HNO}_3 = \frac{4}{3} \times \text{Moles of KNO}_3 = \frac{4}{3} \times 1.089 \approx 1.452 \, \text{mol}\)

1. Calculate the mass of \(\text{HNO}_3\) required.

The molar mass of \(\text{HNO}_3\) is 63 g/mol.

\(\text{Mass of HNO}_3 = \text{moles} \times \text{molar mass} = 1.452 \, \text{mol} \times 63 \, \text{g/mol} \approx 91.4 \, \text{g}\)

The closest option to our calculated mass is 91.5 g. Therefore, the correct answer is 91.5 g.

Hence, the amount of \(\text{HNO}_3\) required is 91.5 g.

Answer 2

\(4\text{HNO}_3(\text{l}) + 3\text{KCl}(\text{s}) \rightarrow \text{Cl}_2(\text{g}) + \text{NOCl}(\text{g}) + 2\text{H}_2\text{O}(\text{g}) + 3\text{KNO}_3(\text{s})\)

\(\because 110 \, \text{g of KNO}_3 \Rightarrow \text{moles of KNO}_3 = \frac{110}{101} = 1.089 \, \text{mol}\)

As, \(4 \, \text{mol of HNO}_3 \text{ produces } 3 \, \text{mol of KNO}_3\).
\(\text{Hence, the moles of HNO}_3 \text{ required to produce } 1.089 \text{ moles of KNO}_3 =\)
\(=43×1.089=1.452 mol\)
\(\text{Hence, mass of HNO}_3 \text{ required} = 1.452 \times 63\)
\(≃ 91.5 g\)
So, the correct option is (C): \(91.5\ \text{g}\)