Question

The equivalent mass of $BaCr{O}_4$ used as an oxidizing agent in acidic medium is (Atomic mass of $Ba=137.34$ amu and $Cr=52$ amu) :

• A. $137.34$
• B. $84.44$
• C. $114.45$
• D. $68.67$

Answer 1

Answer: (B)

$84.44$

The molar mass of barium chromate is $137.34+52+64=253.34$ g/mol.
The oxidation number of $Cr$ changes from $+6$ to $+3$.
The change in the oxidation number is $3$.
The equivalent mass of barium chromate is $\frac{\text{Molar mass of barium chromate}}{\text{Change in the oxidation number of Cr}}=\frac{253.34}{3}=84.44$.