2.0 g of hydrogen react with 16.0 g of oxygen to form 18.0 g of water. If 3.0 g of hydrogen reacts with 16.0 g of oxygen, which of the following is true?
A) 18.0 g of water will form with 1.0 g of excess oxygen.
B) 18.0 g of water will form with 1.0 g of excess hydrogen.
C) 19.0 g of water will form.
D) 17.0 g of water will form with 1.0 g of excess oxygen and 1.0 g of excess hydrogen.
E) None of these are correct.

Question

Quizplus · Accepted Answer

The ratio of hydrogen to oxygen in water is 2:1. Therefore, if 3.0 g of hydrogen reacts with 16.0 g of oxygen, all the hydrogen will be used up and 1.5 times that amount of oxygen (i.e. 3.0 x 1.5 = 4.5 g) will also be used up. This leaves 11.5 g of oxygen, which is in excess. Since the excess oxygen cannot react with anything else, it will remain unchanged. Thus, the remaining 11.5 g of oxygen will combine with the 1.0 g of hydrogen that was not used up to form 12.5 g of water. Therefore, 18.0 g of water will form with 1.0 g of excess hydrogen, which is choice B.

20 G of Hydrogen React with 16