Suppose that 25 g of each substance is initially at 27.0 °c. what is the final temperature of each substance upon absorbing 2.35 kj of heat?

a. gold

b. silver

a. gold : 755.7°C.

b. silver: 418.7°C.

Explanation:

a. gold:

It is known that:

The amount of heat absorbed by gold = Q = m. c.ΔT.

where, m is the mass of Au (m = 25.0 g).

c is the specific heat capacity of Au = 0.129 J/g°C.

ΔT is the temperature difference = (final T - 27.0°C).

Q = 2.35 kJ = 2350.0 J.

∴ The amount of heat absorbed by Au = Q = m. c.ΔT = 2350.0 J.

∴ 2350.0 J = (25.0 g) (0.129 J/g°C) (final T - 27.0°C).

∴ 2350.0 J = 3.225 final T - 87.08.

∴ 3.225 final T = 2350.0 + 87.08 = 2473.

∴ final T = 2473/3.225 = 755.7°C.

b. silver:

It is known that:

The amount of heat absorbed by silver = Q = m. c.ΔT.

where, m is the mass of Ag (m = 25.0 g).

c is the specific heat capacity of Ag = 0.24 J/g°C.

ΔT is the temperature difference = (final T - 27.0°C).

Q = 2.35 kJ = 2350.0 J.

∴ The amount of heat absorbed by Ag = Q = m. c.ΔT = 2350.0 J.

∴ 2350.0 J = (25.0 g) (0.24 J/g°C) (final T - 27.0°C).

∴ 2350.0 J = 6.0 final T - 162.0.

∴ 6.0 final T = 2350.0 + 162.0 = 2512.

∴ final T = 2512/6.0 = 418.7°C.