gasoline is produced from crude oil, a nonrenewable resource. Ethanol is mixed with gasoline to produce a fuel called gasahol. Calculate the mass of water produced when 100.0 g of ethanol, C2H5OH, is burned in 82.82 g of oxygen.

46.58 g of H₂O

Solution:

The Balance Chemical Equation is as follow,

C₂H₅OH + 3 O₂ → 2 CO₂ + 3 H₂O

Step 1: Calculate the Limiting Reagent,

According to Balance equation,

46.07 g (1 mol) C₂H₅OH reacts with = 96 g (3 mol) of O₂

So,

100 g of C₂H₅OH will react with = X g of O₂

Solving for X,

X = (100 g * 96 g) : 46.07 g

X = 208.3 g of O₂

It means 100 g of C₂H₅OH requires 208.3 g of O₂, while we are provided with 82.82 g of O₂ which is less than required. Therefore, O₂ is the limiting reagent and will control the yield of products.

Step 2: Calculate amount of Water produced,

According to equation,

96 g (3 mol) of O₂ produces = 54 g (3 mol) of H₂O

So,

82.82 g of O₂ will produce = X moles of H₂O

Solving for X,

X = (82.82 g * 54 mol) : 96 g

X = 46.58 g of H₂O