How many moles of HNO₃ will be produced from the reaction of 45.0 g of NO₂ with excess water in the following chemical reaction? 3 NO₂(g) + H₂O (l) → 2 HNO₃(g) + NO(g)

Answer 1

This is a good example of a dimensional analysis question! The first step is to determine how many moles of NO2 are in 45.0g. For this, we need the molar mass of NO2 which is 46.0g.

Therefore, there are 45.0g NO2 (1 mol of NO2/46.0g) = 0.978 mol of NO2.

Because there is excess water, we just need to look at the NO2 in the reactants. Now, we use the ratio that we can find from the equation to see how many moles of HNO3 are produced from how many moles of NO2.

According to the equation, 3 moles of NO2 produce 2 moles of HNO3. Next, we use dimensional analysis to find the answer: 0.978 mol of NO2 (2 mol of HNO3/3 mol of NO2) = 0.978 (2/3) mol of HNO3 = 0.652 mol of HNO3.

The answer is that 45.0g of NO2 produce 0.652 mol of HNO3 according to the reaction as shown.