Question

Calculate the mass of NH4NO3 salt that should be combined with 100.0 mL of water to obtain a temperature decrease of exactly –15.0C?

Delta H of the solution = 24.13 Ccal = 21.12 Csh2o = 4.18 average Qrxn = 1151.6

I don't understand how to solve it

Answer 1

You need to put some units on the numbers. Where does Qrxn come from? What kind of reaction?