Question

How much solid oxalic acid (molecular weight $126$) has to be weighed to prepare $100$ mL of exactly $0.1$ N oxalic acid solution in water?

• A. 1.26 g
• B. 0.126 g
• C. 0.63 g
• D. 0.063 g

Answer 1

The Correct Option is C

To prepare a solution of given normality, we use the formula:

Weight (g) = Normality × Equivalent weight × Volume (L) 

Given:
Normality (N) = 0.1
Volume = 100 mL = 0.1 L
Molecular weight of oxalic acid ($H_2C_2O_4$·2H₂O) = 126
Since oxalic acid is a dibasic acidn-factor = 2
So, Equivalent weight = $\dfrac{126}{2} = 63$ 

Now calculate the required weight: 
Weight = $0.1 \times 63 \times 0.1 = \mathbf{0.63\ g}$ 

Answer: 0.63 g