A)how many moles of o2 are required for the complete combustion of 2.2 g of c3h8 to form co2 and h2o?
b)a 65.25 g sample of cuso4•5h2o (m = 249.7) is dissolved in enough water to make 0.800 l of solution. what volume of this solution must be diluted with water to make 1.00 l of 0.100 m cuso4?

A)How many moles of O2 are required for the complete combustion of 2.2 g of C3H8 to form CO2 and H2O?

C3H8 + 5O2 = 3CO2 + 4H2O

2.2 g C3H8 ( 1 mol / 44.11 mol ) ( 5 mol O2 / 1 mol C3H8) = 0.25 mol O2

b)A 65.25 g sample of CuSO4•5H2O (M = 249.7) is dissolved in enough water to make 0.800 L of solution. What volume of this solution must be diluted with water to make 1.00 L of 0.100 M CuSO4?

M1V1 = M2V2
[65.25 ( 1 / 249.7 )/ 0.800 L] (V1)= 0.100  (1.00 L)
V1 = 0.31 L or 310 mL