The specific heat capacity of silver is 0.24 J/°C·g.?

Question

(a) Calculate the energy required to raise the temperature of 140.0 g Ag from 273 K to 295 K.
J

(b) Calculate the energy required to raise the temperature of 1.0 mol Ag by 1.0°C (called the molar heat capacity of silver).
J/mol°C


(c) It takes 1.35 kJ of energy to heat a sample of pure silver from 12.0°C to 15.7°C. Calculate the mass of the sample of silver.
g

Answer 1

Q = mass x specific heat x delta T
1) Q = 140.0 g x 0.24 J/°C g x ( 295 - 273 ) = 739 J

2) 1 mole of Ag weights 107.868 g
Q = 107.868 g x 0.24 J/°C g x 1 = 25.89 J

c) 1.35 kJ = 1350 J
1350 = mass Ag x 0.24 ( 15.7 - 12.0 ) = mass Ag x 0.888
mass Ag = 1350 / 0.888 = 1520 g

Answer 2

Energy required = amount x change in T x specific heat

a) You are told g and specific heat per g
b) Just like (a), but you need to look up the required mass
c) Use same equation, but this time mass is your unknown.