The temperature of 5 ml of strong acid increases by 5°c when 5ml of a strong base is added to it. If 10 ml of each is mixed, temperature should increase by- (neglect the m₁s₁ value of the vessel)

When 5 ml of strong acid reacting with 5ml of strong base, net heat evolved = $∆\mathrm{H}$
$\therefore$Temperature increases $= \frac{∆\mathrm{H}}{\mathrm{ms}}$
When 10 ml of each are reacting, the heat evolved = 2$∆\mathrm{H}$ ; but mass of the solution =2m
$\therefore$Temperature increases $=\frac{2\mathrm{\Delta H}}{2\mathrm{ms}}=\frac{\mathrm{\Delta H}}{\mathrm{ms}}$