Statement - The water pouch of instant cold pack for treating athletic injuries breakes when squeezed and `NH_(4)NO_(3)` dissolves lowering the temperature.
Explanation - Addition of non-volatile solute into solvent results into depression of freezing point of solvent.

Options

A. Both (A) and (R ) are true and (R ) is the correct explanation of (A)
B. Both (A) and (R ) true but (R ) is not the correct explanation of (A)
C. (A) is true, but (R ) is false
D. (A) is false, but (R ) is true

Answer

A

Explanation

`M_(1)V_(1)+M_(2)V_(2)=MV`
`800xx0.5+200xx1=1000 V`
`(400+200)/(1000)=V`
`V=0.6 M`