Question

The molar heat of fusion for water is 6.009 kJ/mol. Express this heat of fusion in Joules per gram. 1. 0.3453 J/g 2. 400.3 J/g 3. 287.5 J/g

Answer 1

Answer:

333.46 J/g

Explanation:

To convert from kiloJoules per mole to kiloJoules per gram, first we convert to Joules per mole:

6.009 kJ/mol * 1000 = 6009 J/mol

1 mole of water contains 18.02 grams of water, hence:

(1 J/mol) / (1 mol) * (1 mol) / (18.02g)

Therefore:

(6009 J/mol) / (1 mol) * (1 mol) / (18.02g)

= 333.46 J/g

Another way of seeing this is, to convert from Joule per mole to Joules per gram, divide by the number of grams in one mole. In the case of water, it's 18.02 grams in one mole.

Answer 2

Answer:

333.8J/g

Explanation:

Let's convert them separately.

1kJ = 1000J

mole = mass/molar mass

molar mass of water = 18g/mole

mass = mole × 18g/mole

mass = 18g

Overall conversion is

[6.009KJ × (1000J/1KJ)]/[mole × 18g/mole]

6009J/18g

= 333.8J/g

The closest answer is 400.3J/g