Ammonia chemically reacts with oxygen gas to produce nitric oxide and water . What mass of water is produced by the reaction of of ammonia? Be sure your answer has the correct number of significant digits.

Full Question:

Ammonia chemically reacts with oxygen gas to produce nitric oxide and water. What mass of water is produced by the reaction of 7.7g of ammonia?

Be sure your answer has the correct number of significant digits.

12.23g ≈ 12g (2 s.f)

Explanation:

Ammonia chemically reacts with oxygen gas to produce nitric oxide and water. The balanced chemical reaction is given as:

4 NH3 + 5 O2 >  4 NO + 6 H2O

From the reaction;

4 mole of ammonia reacts to produce 6 moles of water

From the question;

Moles = mass / molar mass

From the question;

moles of ammonia = mass / molar mass = 7.7 / 17 = 0.4529moles

Number of moles of water produced;

4 = 6

0.4529 = x

x = (0.4529 * 6 )  / 4

x = 0.67935moles

Mass of water =  moles * molar mass = 0.67935 * 18 = 12.23g ≈ 12g (2 s.f)