Question

Calculate the amount of heat evolved when $500c{m}^3$ of $0.1$ M HCl is mixed with $200$ $c{m}^3$ of $0.2$ M NaOH.

• A. $57.3$ kJ
• B. $2.865$ kJ
• C. $2.292$ kJ
• D. $0.573$ kJ

Answer 1

The correct option is C $2.292$ kJ

$500c{m}^3$ of 0.1 M HCl corresponds to $0.5\times 0.1=0.05$ moles of hydrogen ions.

$200c{m}^3$ of 0.2 M NaOH corresponds to $0.2\times 0.2=0.04$ moles of hydroxide ions.

sodium hydroxide is completely neutralize by Hcl

The enthalpy of neutralisation is 57.3 kJ/mol. For 0.04 moles, the enthalpy of neutralisation is $0.04\times 57.3=2.292kJ$

Hence, option C is the correct answer.