Question

The amount of heat released when $20\, mL$ of $0.5 \,M \,NaOH$ is mixed with $100 \,mL$ of $0.1 \,M \,HCl$ is $x \,kJ$. The heat of neutralisation (in $kJ \,mol ^{-1}$ ) is

• A. -100 x
• B. -50 x
• C. #ERROR!
• D. #ERROR!

Answer 1

Answer: (A)

-100 x

Answer 2

Equivalents of $N a O H=\frac{20 \times 0.5}{1000}=0.01$ Equivalents of $H C l=\frac{100 \times 0.1}{1000}=0.01$ $0.01$ equivalents, of acid and base release heat $=-x\, k J$ $\therefore 1$ equivalents of acid and base release heat $=\frac{-x}{0.0 .1} \times 1=-100\, x\, k J$