Question

5. The quantity of oxalic acid required to prepare 0.1 M 100 mL standard solution of oxalic acid
is
a. 126 g
b. 12.6 g
d. 0.126 g
c. 1.26​

Answer 1

Answer:

This is taken as primary standard for acids as it can be weighed accurately. To prepare 1000 ml of 1 N Oxalic acid solution, the amount of oxalic acid required = 63 g. Therefore, to prepare 1000 ml of 0.1 N Oxalic acid solution, the amount of oxalic acid required = 6.3 g

Answer 2

Answer:

The quantity of oxalic acid required to prepare 0.1 M 100 mL standard solution of oxalic acid is 1.26g

Explanation:

Molecular formula of oxalic acid = C₂H₂0₄.2H₂O

Molecular mass of oxalic acid = 1×2+2×12+4×16+2×(1×2+16)

Molecular mass of oxalic acid = 2+24+64+2×(18)

Molecular mass of oxalic acid = 2+24+64+36

Molecular mass of oxalic acid = 126 g/mol

We know that, the total number of moles of solute in one litre of a particular solution is known as its molarity.

∴ Molarity = No. of moles/ Volume of solution in liters

Now, let the weight of oxalic acid to be X.

Molarity = Weight × 1000 / Molecular mass × Volume

Molarity = X × 1000 / Molecular mass × Volume

Molarity = X  × 1000 / 126  × 100

0.1 = X  × 1000 / 126  × 100

X = 1.26g

Hence, to prepare 100ml of Oxalic Acid solution 1.26g of oxalic acid is required.

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