Question

When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 25.2 g of carbon were burned in the presence of 81.4 g of oxygen, 14.2 g  of oxygen remained unreacted. What mass of carbon dioxide was produced? Express your answer to one decimal place and include the appropriate units.

A sample of sodium reacts completely with 0.284 kg of chlorine, forming 468 g of sodium chloride. What mass of sodium reacted? Express your answer to three significant figures and include the appropriate units.

Calculate the mass of water produced when 1.36 g of butane reacts with excess oxygen. Express your answer to three significant figures and include the appropriate units.

Calculate the mass of butane needed to produce 61.5 g of carbon dioxide. Express your answer to three significant figures and include the appropriate units.

Answer 1

C + O2 ---> CO2

no of mol of O2 reacted = (81.4-14.2)/32 = 2.1 mol

no of mol of co2 produced = 2.1 mol

mass of CO2 produced = 2.1*44 = 92.4 g

2Na + Cl2 ----> 2NaCl

no of mol of NaCl produced = 468/58.5 = 8

no of mol of Na reacted = 8 mol

mass of Na reacted = 8*23 = 184 g

2c4h10 + 14o2 ---> 8co2 + 10h2o

no of mol of butane = 1.36/58 = 0.0234 mol

no of mol of water produced = 0.0234*10/2 = 0.117 mol

mass of water produced = 0.117*18 = 2.106 g

2c4h10 + 14o2 ---> 8co2 + 10h2o

no of mol of CO2 produced = 61.5/44 = 1.4 mol

no of mol of butane reacted = 1.4*2/8 = 0.35 mol

mass of butane reacted = 0.35*58 = 20.3 g