Some Basic Concepts Of Chemistry Question 137
Question: What weight of $ H _2C _2O _42H _2O(mol\text{.},wt\text{.},=126) $ should be dissolved to prepare 250 ml of cent normal to be used as a reducing agent?
Options:
A) 0.63 gm
B) 0.1575 gm
C) 0.126 gm
D) 0.875 gm
Show Answer
Answer:
Correct Answer: B
Solution:
[c] Per mole of given acid $ C _2O_4^{2-} $ present = 1 mole
$ \therefore $ $ C _2O_4^{2-}\to CO _2+2e $
$ \therefore $ x factor for $ H _2C _2O _4,2H _2O $ as a reducing agent = 2
$ \therefore $ equiv. wt. $ =\frac{250}{100}\times {10^{-3}}=63 $ 250 ml of seminormal solution $ =\frac{250}{100}\times {10^{-3}} $ equiv.
$ \therefore $ wt. of $ H _2C _2O _4,2H _2O $ required $ =\frac{250}{100}\times {10^{-3}}\times 63gm=0.1575gm $
