Question

sample of substance X has a mass of 326.0 g releases 4325.8 cal when it freezes at its freezing point. If substance X has a molar mass of 58.45 g/mol, what is the molar heat of fusion for substance X?

Answer 1

Answer:

C. 775.6 cal/mol

Explanation:

To put it straight forward

Answer 2

Number of moles ( substance x ):

1 mole --------- 58.45 g/mol
? mole --------- 326.0 g

326.0 x 1 / 58.45 => 5.577 moles

 heat of fusion:

hf = Cal / moles

hf = 4325.8 Cal / 5.577 moles

hf = 775.65 cal/mol

hope this helps!