Question

Two elements $X$ (at. mass 1$6$) and $Y$ (at. mass $14$) combine to form compounds $A$, which combine with a fixed mass of $X$ in $A,B$ and $C$ is $1:3:5$.

If $32$ parts by mas of $X$ combines with 84 parts by mass of $Y$ in $B$, then in $C$ $16$ parts by mass of $X$ will combine with:

• A. $14$ parts by mass of $Y$
• B. $42$ parts by mass of $Y$
• C. $70$ parts by mass of $Y$
• D. $84$ parts by mass of $Y$

Answer 1

The correct option is C $70$ parts by mass of $Y$

The ratio of different masses of Y which combines with a fixed mass of X in A, B and C is $1:3:5$.

32 parts by mass of X combines with 84 parts by mass of Y to form B.

Hence, 16 parts of the mass of X combine with 42 parts by mass of Y.

The ratio of Y in B & C is $3:5$.

16 parts by mass of X combines with $42\times \frac{5}{3}=70$ parts by mass of Y to form C.

So, the correct option is $C$