Question

Potash is any potassium mineral that is used for its potassium content. Most of the potash produced in the United States goes into fertilizer. The major sources of potash are potassium chloride $\left(KCl\right)$ and potassium sulphate $\left(K_{2}S{O}_4\right)$. Potash production is often reported as the potassium oxide $\left(K_{2}O\right)$ equivalent or the amount of $K_{2}O$ that could be made from a given mineral. $KCl$ costs Rs. $50$ per kg.

What is the cost in rupees of $K$ per mole of the $KCl$ sample?

• A. $13.42$
• B. $3.73$
• C. $1.00$
• D. $2.00$

Answer 1

Answer: (B)

$3.73$

From the given data, we know that
$KCl$ costs Rs. $50$ per kg $=$ Rs. $0.05$ per g $=$ Rs. $3.73$ per mol
Also,
Potash production is often reported as the potassium oxide $\left(K_{2}O\right)$ equivalent or the amount of $K_{2}O$ that could be made from a given mineral.
Therefore, $1$ mole $K_{2}O$ $\equiv$ $2$ mole $KCl$ $\equiv$ $2$ g-atom of $K$
Hence, $1$ mole $KCl$ $\equiv$ $1$ g-atom of $K$
Therefore, cost of $K$ per mole of $KCl$ sample = Rs. $3.73$ per mol