Question

If $xg$ of an element $A$ contains $\frac{y}{80}$ atoms and $2xg$ of an element $B$ contains $\frac{y}{40}$ atoms then the ratio of atomic weights of two elements $A$ and $B$ is:

• A. $1:1$
• B. $1:4$
• C. $4:1$
• D. $2:1$

Answer 1

The correct option is A $1:1$

Let the atomic mass of $A$ be $M_A$ and $B$ be $M_B$

Given, $\frac{x}{M_A}\times N_A=\frac{y}{80}....\left(i\right)$ ($N_A$ is avogadro number)

$\frac{2x}{M_B}\times N_A=\frac{y}{40}.....\left(ii\right)$

$\left(i\right)/\left(ii\right)\Rightarrow \frac{M_A}{M_B}=1:1$