Question

On analysis, a certain compound was found to contain iodine and oxygen in the ratio of 254 : 80. The formula of the compound is:

(At. mass of $I=127$, $O=16$)

• A. $IO$
• B. $I_{2}O$
• C. $I_5{O}_2$
• D. $I_2{O}_5$

Answer 1

Answer: (D)

$I_2{O}_5$

The compound will contain 254 g of iodine for every 80 g of oxygen.

The number of moles of iodine $=\frac{\text{254 g}}{\text{127 g}}=\text{2 mol}$.

The number of moles of oxygen $=\frac{\text{80 g}}{\text{16 g}}=\text{5 mol}$.

The mole ratio iodine : oxygen $=2:5$.

The formula of the compound is $I_2{O}_5$.