A student places 5.77 grams of wex (a mythical substance often burned for light on other planets) in a test tube and then melts it. When the wex starts to freeze, the test tube (with the wex) is put into 237.6 g of water at 34.7oC. If the final temperature of the water is 51.9oC, what is the heat of fusion of the wex in cal/g?

I got 709 as an answer... is this correct?

That's the same answer I have.

Thank you!

To calculate the heat of fusion of the wex in cal/g, we need to use the formula:

q = m × c × ΔT

Where:
q = heat absorbed or released (in calories)
m = mass of the substance (in grams)
c = specific heat capacity of the substance (in cal/g°C)
ΔT = change in temperature (in °C)

First, let's determine the heat absorbed or released by the water using the given information:

m_water = 237.6 g (mass of water)
c_water = 1 cal/g°C (specific heat capacity of water)
ΔT_water = 51.9°C - 34.7°C = 17.2°C (change in temperature of water)

q_water = m_water × c_water × ΔT_water
= 237.6 g × 1 cal/g°C × 17.2°C
= 4087.04 calories

Next, we need to determine the heat absorbed or released by the wex. Since the wex goes through a phase change (from solid to liquid), we need to account for the heat of fusion (ΔH_fusion) in our calculation. The formula becomes:

q_wex = m_wex × ΔH_fusion

We know the mass of the wex (5.77 grams), so we need to solve for ΔH_fusion.

However, we have a missing piece of information. We need to know the change in temperature of the wex during the phase change. Once we have that, we can calculate ΔH_fusion.

Please provide the change in temperature of the wex during the phase change, and I'll be able to help you further.