Question

Methane, CH4, burns completely in oxygen to yield carbon dioxide and water. 1. how many grams of carbon dioxide can be formed from 16.0g of methane and 48.0g of oxygen?   

2. how much excess reagent will be left unreacted?

3. if only 30.0g of carbon dioxide are formed, what is the percent yield of the reaction?

Answer 1

1)

balanced reaction :

CH4    + 2O2 -----------------------> CO2 + 2H2O

16g           64g                            44 g        36g

16g           48 g

limiiting reagent is O2 . the amount of excess reagent consumed

CH4 reacted = 16 x 48 / 64 = 12 g

mass of CO2 formed = 44 x 48 / 64 = 33 g

amount of CO2 formed = 33 g

2)

excess reagent left = 16 -12 = 4 g

3)

percent yield = actual yield x 100 / theroretical yield

                     = 30.0 x 100 / 33

                    = 90.9 %