Question

What mass of silver (in grams) is solidified when 749 joules of heat are released by a sample of molten silver at its freezing point of 962°C? The heat of fusion of silver is 109 J/g. Round your answer to the nearest hundredth.

Answer 1

The correct answer is 6.87 grams  Q/Lf=m 

Answer 2

heat released Q = 749 joules

heat of fusion of silver L = 109 J/g

Here phase of silver is changing from liquid to solid

so temperature will remain same

all heat will be released due to its phase change

and in this case we use Q=mL

where m is the mass of silver in gram

Q= mL

749 = m * 109

m = 749/109

m = 6.87 gram