Consider the equation 4NH 3+ 7O 2----->4NO 2+6H 2 O?

Question

How many grams of oxygen are necessary to produce 4.5 moles of NO2?

How many molecules of water are produced when 2.25 moles of ammonia are completely reacted?

Answer 1

You already have a balanced equation.

The stoichiometry is based on the molar ratios.

7 moles of O2 will produce 4 moles of NO2. Convert the grams of NO2 to moles. Multiply by the molar ratio and that gives you moles of O2. Then convert that to grams

Do the same approach with the ammonia and water.

Answer 2

x/7 = 4.5/4
x = 7.875 moles O2
(7.875)(32) = 252 g O2

x/6 = 2.25/4
x = 3.375 moles H2O
(3.375)(6.022*10^23) =
2.032425*10^24 molecules