Free Response # 1 b and d have the word acetone in the problem. Acetone should be caffeine. 

Thanks,

Hi Nicholas,
Yes you are correct!  We will fix this. Thank you.

Free Response #2 answers a and b should be: 
2.a. 0.004 g/mL and 4 g/L
2.b. 0.022 mol
Thanks,

Hi Nicholas,
Yes you are correct again!  We will fix this. Thank you.