Heat of mixing: will the change in temperature increase or decrease if the volume is increased?

Question

If two solutions are mixed and the temperature change is 0.86 degrees celsius, then how can we predict the temperature change if the volumes of each solution is doubled? Will the temperature change also double, or will it decrease?

Answer 1

The temperature change will be the same.  Doubling the volume of each solution also doubles the mass of each.  The amount of heat released will double, but there will be twice as much mass to absorb it.