Answer:
[tex]\boxed {\boxed {\sf 50.1 \ kJ}}[/tex]
Explanation:
When water changes from ice (solid) to water (liquid), it is melting or fusion. Therefore, we can use the following formula to find energy:
[tex]q=mH_f[/tex]
where q is the energy, m is the mass, and Hf is the heat of fusion.
1. Define Values
The mass is 150 grams. The heat of fusion for water is 334 Joules per gram.
[tex]m= 150 \ g \\H_f=334 \ J/g[/tex]
2. Calculate Energy
Substitute the values into the formula.
[tex]q=150 \ g * 334 \ J/g[/tex]
Multiply. Note that the grams (g) will cancel each other out and leave Joules as our units.
[tex]q=150 *334 \ J[/tex]
[tex]q=50100 \ J[/tex]
3. Convert Units
We found the answer in joules, but the question asks for kilojoules, so we must convert.
There are 1000 Joules in 1 kilojoule. Therefore, we can divide the joules calculated by 1000.
[tex]50100 \ J *\frac{1 \ kJ}{1000 \ J}[/tex]
[tex]\frac{50100 \ kJ}{1000 \ }[/tex]
[tex]50.1 \ kJ[/tex]
50.1 kilojoules are needed to change 150 grams of ice to water.
