Answer:
10.44 °C
Explanation:
When the thermal equilibrium is reached, both of the substances have the same final temperature (T). The liquid water will lose heat, and the ice cube will absorb this heat. The temperature of the ice will increase until it reaches 0°C, at this temperature, it will change of phase for liquid, absorbing heat, but without a change in the temperature. Then the temperature will increase until the equilibrium.
By the energy conservation, the total amount of heat must be equal to 0:
Qice + Qmelting + Qliquid1 + Qliquid2 = 0
Liquid 1 is the ice after melting, and liquid 2 the liquid that was already at the flask. When there's a change of temperature:
Q = n*c*ΔT, where n is the number of moles, c is the heat capacity and ΔT is the temperature change (final - initial). The temperature variation in °C is equal in K, so the temperature may be used in °C.
The melting heat is:
Q = n*Hfus, Hfus = 6007 J/mol
The molar mass of the water is 18 g/mol, so the number of moles of the water and the ice are:
nwater = nliquid1 = 360/18 = 20 moles
nice = 36/18 = 2 moles
Qice + Qmelting + Qliquid1 + Qliquid2 = 0
2*38*(0 - (-10)) + 2*6007 + 2*75*(T - 0) + 20*75*(T - 20) = 0
760 + 12014 + 150T + 1500T - 30000 = 0
1650T = 17226
T = 10.44 °C
