You take 322 g of a solid (melting point = 57.2°C, heat of fusion = 349 J/g) and let it melt in 753 g of water. The water temperature decreases from its initial temperature to 57.2°C. Calculate the initial temperature of the water.

Question

Quizplus · Accepted Answer

We can use the equation:

q = m_water*C_water*(T_final - T_initial)

where q is the heat transferred, m_water is the mass of water, C_water is the specific heat capacity of water, T_final is the final temperature (57.2°C) and T_initial is the unknown initial temperature.

We can also use the equation:

q = m_solid*H_fusion

where q is the heat transferred, m_solid is the mass of the solid, and H_fusion is the heat of fusion.

At the melting point, the solid will transfer all its heat of fusion to the surrounding water and eventually reach a thermal equilibrium.

Therefore, we can write:

m_water*C_water*(T_final - T_initial) = m_solid*H_fusion

Substituting the given values, we get:

753 g * 4.18 J/(g °C) * (57.2 °C - T_initial) = 322 g * 349 J/g

Solving for T_initial, we get:

T_initial = 92.9°C

Therefore, the initial temperature of the water was 92.9°C.

You Take 322 G of a Solid (Melting Point =