Question

When 1942 J of heat energy is added to 47.4 g of ethanol, `C_2H_6O`, the temperature increases by 16.7 °C. What is the molar heat capacity of `C_2H_6O`?

Answer 1

`112 J/(mol °C)`

Explanation:

ethanol has MM=46,06 g/mol, so you have `n= (47,4g)/ (46,6 g/(mol)) = 1,030 mol` of ethanol. Since Q = n Cm (Tf-Ti) , the molar heat capacity of ethanol is
`Cm = Q/ (n(Tf-Ti)) = (1942 J)/ (1,030 mol 16,7 °C) = 112 J/(mol °C)`