What mass of `H_(2)C_(2)O_(4). 2H_(2)O (mol.mass=126)` should be dissoved in water to prepare 250mL of centinormal solution which act as a reducing agent?

Options

A. 0.63 gm
B. 0.1575 gm
C. 0.126 gm
D. 0.875 gm

Answer

B

Explanation

Per mole of given acid `C_(2)O_(4)^(2-) ` present =1 mole
`:. C_(2) O_(4)^(2-) rarr CO_(2) + 2e`
`:. ` x factor for `H_(2)C_(2)O_(4) . 2H_(2)O` as a reducing agent =2
`:.` equiv. wt. `= ( 126)/( 2) = 63`
250 ml of centinormal solution
`= ( 250)/( 100) xx 10^(-3) ` equiv.
wt. of `H_(2)C_(2) O_(4) . 2 H_(2)O` required `- ( 250)/( 100) xx 10^(-3) xx 63 gm = 0.1575 gm`