Question

You take 65.9 g of a solid (melting point = 31.5 °c, heat of fusion = 264 j/g) and let it melt in 675 g of water. the water temperature decreases from its initial temperature to 39.5 °c. ignoring the specific heat of the solid, calculate the initial temperature of the water.

Answer 1

To find the initial temperature of water in a high school Chemistry heat exchange problem, calculate the heat needed to melt a solid by multiplying its mass and heat of fusion, then equate this to the heat lost by water by multiplying the water's mass, specific heat, and the difference between initial and final temperatures.

Step-by-step explanation:

The question is concerned with calculating the initial temperature of water, given that a solid is allowed to melt in it. This is a heat exchange problem typically found in high school Chemistry.

First, we calculate the heat necessary to melt the solid using its mass and heat of fusion:

Q = mass × heat of fusion

Then, we set the heat gained by the solid equal to the heat lost by the water:

Q = (mass of water) × (specific heat of water) × (initial temperature of water - final temperature of water)

Solving for the initial temperature of the water, we can substitute the known values and compute the initial temperature. Since the entire system does not exchange heat with the surroundings, the heat released by the water will be equal to the heat absorbed by the solid to melt.