The heat of neutralization if strong acid and strong base is -60kj. The heat released by mixing 0.5 moles of HCL and 0.2 moles of NaOH would be

Dear student,
The reaction is:
HCl + NaOH--> NaCl+H2O
out of 0.5 moles of HCl, 0.2 moles will react with 0.2 moles of NaOH and 0.3 moles of HCl remain unreacted.
So, when 1 mole of HCl is neutralised by 1 mole of NaOH, heat released is 60 kJ. SO when 0.2 moles of HCl is neutralised by 0.2 moles of NaCl, then heat released is 60 * 0.2 = 12kJ.
So heat released is 12 kJ. [Ans]
Regards,
Thank You,
Soumya Ranjan Mohanty.