Question

Suppose that 23 g of each of the following substances is initially at 26.0 ∘C. What is the final temperature of each substance upon absorbing 2.25 kJ of heat?

For:

a) gold

b) silver

c) aluminum

d) water

Answer 1

We will use the equation Q = m*c_p*T where Q is the heat supplied, c_p is specific heat capacity and T is the change in temperature.

Q = 2.25 kJ = 2.25 kJ * 1000 J/kJ = 2250 J, m = 23g

a) For gold, c_p = 0.129 J/g C. Substitute the values for Q, m and cp in the equation, we get T = 758.34 C = T_final - 26 C.

T_final = 758.34 + 26 C = 784.34 C.

b) Similarly for Silver, c_p = 0.240 J/g C.

T = 407.6 C. T_final = 407.6 + 26 C = 433.6 C.

c) For Aluminum, c_p = 0.9 J/g C.

T = 108.7 C. T_final = 108.7 + 26 C = 134.7 C.

d) For water, c_p = 4.184 J/g C.

T = 23.38 C. T_final = 23.38 + 26 C = 49.38 C.