Question

The amount of ${FeSO}_4.{7H}_{2}O$ to be weighed to prepare a solution of 100ml of 0.1 M concentration is:

[Mol.wt. of ${FeSO}_4.{7H}_{2}O=278$]

• A. $27.8$
• B. $90$
• C. $2.78$
• D. $5.5$

Answer 1

The correct option is C $2.78$

$Molarity=\frac{weight}{Mwt}\times \frac{1000}{V\left(ml\right)}$

$0\cdot 1=\frac{weight}{2\cdot 78}\times \frac{1000}{100}$

$weight=278\times 0\cdot 1$

$=2\cdot 78gm$