An 80g sample of 3 1 H decays, leaving 2.5g of 3 1 H. 1. How long would this take?
2. What percentage of this sample would be left?
3. What fraction of this sample would be left?

3 1 H -> 3 2 He + 0 -1 /3 t1/2= 12.3 years

A5 mole sample of liquid acetone is converted to a gas at 75.0°c. if 628 j are required to raise the temperature of the liquid to the boiling point, 15.600 kj are required to evaporate the liquid, and 712 j are required to raise the final temperature to 75.0°c, what is the total energy required for the conversion?