When 86.7 of water at a temperature of 73.0 C is mixed with an unknown mass of water at a temperature at 22.3 C final temperature of the resulting mixture is 61.7 C. What was the mass of the second sample water

Can someone me with these questions plz.

Isopropyl alcohol, (ch3)2choh, is a common solvent. determine the percent by mass of hydrogen in isopropyl alcohol. a) 6.71% h b) 13.4% h c) 25.0% h d) 53.3% h

Match each term to its description. match term definition excess reactant a) reactant that can produce a lesser amount of the product limiting reactant b) amount of product predicted to be produced by the given reactants theoretical yield c) reactant that can produce more of the product