Butane, C4H10 , reacts with oxygen, O2 , to form water, H2O , and carbon dioxide, CO2 , as shown in the following chemical equation:2C4H10(g)+13O2(g)→10H2O(g)+8CO2(g)

The coefficients in this equation represent mole ratios. Notice that the coefficient for water (10) is five times that of butane (2). Thus, the number of moles of water produced is five times the number of moles of butane that react. 

A-Calculate the mass of water produced when 8.89 g of butane reacts with excess oxygen.Express your answer to three significant figures and include the appropriate units.

B-Calculate the mass of butane needed to produce 73.9 g of carbon dioxide.Express your answer to three significant figures and include the appropriate units.