Question

The sulphate contains 9.87 % of M . this sulphate is isomorphous with ZNSO4.7H2O the atomic weight of M is :

Answer 1

1. Let x be the mass of M
Mass of S = 32
Mass of 4 O = 64
Mass of 7 $H_{2}O$ = 126

2. This sulfate is isomorphous with $ZnS{O}_4.7H_{2}O$ means, its structure is $MS{O}_4.7H_{2}O$

3. Thus, MSO4MSO_
​ molecular mass of $MS{O}_4.7H_{2}O$ = x+32+64+126=222 + x

4. It is given that 9.87% of total weight =x,

5. That is, $\frac{9.87}{100}+222x=x$

$9.87+222x=100x$

$x=24.3\left(atomicmassofmetal\right)$