If 2.50 grams of ethane is allowed to react with 5.00 grams of oxygen how many grams of water would be expected?

The mass of water produced is 4.29 g.

Explanation:

Given;

reacting mass of ethane, C₂H₆ = 2.5 g

reacting mass of oxygen, O₂ = 5.0 g

The balanced combustion reaction is given as follows;

2C₂H₆   +   7O₂ >  4CO₂    +   6H₂O

Based on the balanced equation above;

                                     requires

7.0 moles of oxygen >   2.0 moles of ethane

                                   requires

5.0 g of oxygen      >  x gram of ethane

x = (2 x 5) / 7

x = 1.43 g

Ethane is in excess of 1.07g (2.5 g - 1.43g)

Now, determine the mass of water produced by 1.43 g of ethane;

                                   requires

2.0 moles of ethane >   6.0 moles of water

                                   requires

1.43 g of ethane      >  y  gram of water

y = (6 x 1.43) / 2

y = 4.29 g

Therefore, the mass of water produced is 4.29 g.