Question

Equivalent weight of $H_{3}P{O}_4$ in each of the reaction will be respectively:

$H_{3}P{O}_4+O{H}^{-}\to H_{2}P{O}_4^{-}+H_{2}O$
$H_{3}P{O}_4+2O{H}^{-}\to HP{O}_4^{2-}+2H_{2}O$
$H_{3}P{O}_4+3O{H}^{-}\to P{O}_4^{3-}+3H_{2}O$

• A. 98, 49, 32.67
• B. 49, 98, 32.67
• C. 98, 32.67, 49
• D. 32.67, 49, 98

Answer 1

The correct option is A 98, 49, 32.67

$Equivalentweight=\frac{Molecularweight}{NumberofEquivalents}$

In case of:

$H_{3}P{O}_4+O{H}^{-}\to H_{2}P{O}_4^{-}+H_{2}O$

$H^{+}$ ions given = 1

Thus the number of equiv$=1$

$Equivalentweight=\frac{98}{1}=98$

In case of:

$H_{3}P{O}_4+2O{H}^{-}\to HP{O}_4^{2-}+2H_{2}O$

$H^{+}$ ions given = 2

Thus the number of equiv$=2$

$Equivalentweight=\frac{98}{2}=49$

In case of:

$H_{3}P{O}_4+3O{H}^{-}\to P{O}_4^{3-}+3H_{2}O$

$H^{+}$ ions given = 3

Thus the number of equiv$=3$

$Equivalentweight=\frac{98}{3}=32.67$