Answer:
Option A
Explanation:
Let C JK-1 be the heat energy capacity of the calorimeter.
Maa of solution
$=200 mL \times 1g mL^{-1}=200g $
Heat evolved in Exp.I
= $57\times 1000\times 0.1(mol)=5700J$
$\Rightarrow 5700J=(200\times 4.2+C)\times 5.7$
$\Rightarrow 100=200\times 4.2+C$ ......(i)
Let x kJ/mol is heat evolved in neutralisation of acetic acid.
$\Rightarrow x\times 1000\times 0.10=(200\times4.2+C)\times5.6$
$\Rightarrow \frac{x\times 100}{5.6}=200\times4.2+C$ ...........(ii)
From (i) and (ii): x=56 kJ/mol
$\Rightarrow $ Enthalpy of ionisation of acetic acid
= -56-(-57)= 1 kJ/MOL