Question

$KCl$ contains $52\%$ of potassium, $KI$ contains $23.6\%$ of potassium, and $ICl$ contans $77.8\%$ of iodine. What will be the ratio of K and I in $KI$?

• A. 1:2
• B. 1:1
• C. 2:1
• D. None of the above

Answer 1

The correct option is B 1:1

$KCl=52\%K,48\%Cl$
$KI=23.6\&K,76.4\%I$
$ICl=77.8\%I,22.2\%Cl$

In KCl: 48 g of Cl reacts with 52 g of K.

1 g of Cl reacts with $=\frac{52}{48}=1.08$ g of K
In ICl: 22.2 g of Cl reacts with 77.8 g of I
1 g of Cl reacts with $=\frac{77.8}{22.2}$ g of I = 3.5 g of I
Ratio of K and I in KCl and ICl which reacts with fixed mass of Cl(1 g) $=1.08:3.5=\frac{1.08}{1.08}=\frac{3.5}{1.08}=1:3.2$
Ratio of K and I in$KI=23.6:76.4=\frac{23.6}{23.6}:\frac{76.4}{23.6}=1:3.2$
These two ratios are $=\frac{1}{1}:\frac{3.2}{3.2}=1:1$
This proves that they react according to the law of reciprocal proportions.