If 16.00 g of O₂ reacts with 80.00 g NO, how many grams of NO₂ are produced? (enter only the value, round to whole number)

  84 g

Explanation:

The molecular weight of nitrogen is 14.01 g/mol. That of oxygen is 16.00 g/mol, so the weights of the various elements available are ...

From NO

  N: (14.01/(14.01+16.00))·(80 g) = 37.35 g

  O: 80 g -37.35 g = 42.65 g

From O₂

 O: 16 g

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In each mole of NO₂, the weight of the oxygen is 2(16.00) = 32 g. The weight of the nitrogen is 1(14.01) = 14.01 g.

From the available oxygen, we can produce ...

  (42.65 g +16 g)/(32.00 g/mol) = 1.83 mol of NO₂

From the available nitrogen, we can produce ...

  (37.35 g)/(14.01 g/mol) = 2.67 mol of NO₂

Clearly, the reaction is limited by the amount of available oxygen. Then the mass of the NO₂ that can be produced is ...

  (1.83 mol)(32.00 +14.010 g/mol = 84.3 g ≈ 84 g.

84 grams of NO₂ are produced.