Question

An exothermic reaction liberates 7.58 kJ of heat in a coffee cup calorimeter containing 157 grams of solution. The temperature of the solution in the calorimeter increases by 11.2°C. How much heat was absorbed by the calorimeter? Assume the specific heat of the solution is 4.184 J/g•°C.

show work please

a. 223J

b. 7.36kj

c. 657J

d. 5820J

e. -223J

Answer 1

The heat change of the reaction , Q = mcdt

Where

m = mass of the solution = 157 g

c = specific heat of the solution = 4.184 J/g•°C

dt = change in temperature = 11.2 oC

Plug the values we get

Q = 157x4.184x11.2

    = 7357 J

    = 7.357 kJ

Therefore the heat absorbed by the calorimeter is = totall heat liberated - heat of the solution

                                                                       = 7.58 - 7.357 KJ

                                                                       = 0.223 kJ

                                                                       = 0.223 x1000 J                                Since 1 kJ = 1000J

                                                                       = 223 J

Since heat absorbed by the calometer so the heat absorbed by the calorimeter is +223J

Therefore option (a) is correct