Question

How many grams of dibasic acid ($mol$. weight $200$) should be present in $100mL$ of the aqueous solution to give strength $0.1N$?

• A. $10g$
• B. $20g$
• C. $2g$
• D. $1g$

Answer 1

Answer: (D)

$1g$

$Normality=\frac{\text{no. of g - equivalents of solute}}{\text{volume of solution in litre}}$

Given,

$Basicity=2,mol.wt.=200,V=100mL=100/1000L$
$Normality=0.1N$
$Eq.wt.=\frac{mol.wt.}{basicity}=\frac{200}{2}=100$

$N=\frac{mass/eq.wt.}{\text{volume of solution in litre}}$
or $0.1=\frac{mass/100}{100/1000}$
or $0.1=\frac{mass/100}{0.1}$

or $mass=0.1\times 0.1\times 100=1.0g$