Question is below because it is too long...?

Question

When a 19.2-g sample of KCN dissolves in 65.0g of water in a calorimeter, the temperature drops from 28.1 degrees celcious to 15.4 degrees celcious. Calculate the heat per mole for the process.

KCN(s) *arrow* K+(Aq) + CN-(aq)

Answer 1

The heat energy absorbed is ∆T*cp, where cp is the specific heat of water = 4.18J/gºK. The moles of KCN is 65/mm(KCN), where mm(KCN) is the molecular mass of KCN = 65.1

So the answer is [4.18*(28.1-15.4)*65] / [65/65.1]

65g is one mole of KCN so you get 3541J/mole or 828 cal/mole

Answer 2

You look like me.