Using specific heat capacity to find heat

Question

calculate the energy required to heat 1.90 kg of silver from -5.1 C to 16.8 C. Assume the specific heat capacity of silver under these conditions is 0.235 J*g^-1*K^-1

Answer 1

Since silver is a solid at both =5.1ºC and 16.8ºC, there is no phase change to contend with.  Thus, heat (q) is equal to the mass (m) x the specific heat capacity (C) x the change in temperature (∆T). 

q = mC∆T

Using correct units we have 

m = 1.90 kg x 1000 g/kg = 1900 g

C = 0.235 J/g/deg

∆T = 16.8 - (-5.1) = 21.9 degrees

q = (1900 g)(0.235 J/g/deg)(21.9 deg) = 9788 Joules = 9.79 kJ