Question

A compound contains two elements $'X'$ and $'Y '$ in the ratio of $50\%$ each. Atomic mass of $'X'$ is $20$ and $'Y'$ is $40$. What can be its simplest formula?

• A. $XY$
• B. $X_{2}Y$
• C. $XY_{2}$
• D. $X_{2}Y_{3}$

Answer 1

Answer: (B)

$X_{2}Y$

Answer 2

Percentage of element $'X' = 50$, mole ratio $= \frac {50}{20} = 2.5$ Percentage of element $'Y' = 50$, mole ratio $= \frac{50}{40} = 1.25$ For $'X'$, simple ratio $= 2.5/1.25 = 2$ For $'Y'$, simple ratio $= 1.25/1.25 = 1$ Formula $= X_2Y$