You found a shiny rock and want to find out if its gold. the mass(weight) of the rock is 45 g. you put the rock in boiling water, and the you put it in a thermos together with 1.2 dl ethanol. the thermos has the high-capacity of 31 j/k. both ethanol and the thermos had the starting temperature of 18.0°c, and stabilize at 19.5°c after the rock is put in.

how can we use this information to determine if it's gold or not?