.0815 moles NO are reacted with .0789moles O2 gas to form NO2 gas according to the following equation: 2NO +O2=2NO2 determine the molar amounts of NO, O2 and NO2 after complete reaction.
This is a limiting reagent problem. Do you know how to determine which is the limiting reagent? Then you follow standard procedure for a stoichiometry problem.
To determine the molar amounts of NO, O2, and NO2 after the complete reaction, we need to consider the stoichiometry of the balanced chemical equation.
The given balanced chemical equation is:
2NO + O2 → 2NO2
We are given the initial moles of NO and O2 as 0.0815 moles and 0.0789 moles, respectively.
1. Determine the limiting reagent:
To determine the limiting reagent, we compare the stoichiometric ratio of NO to O2 from the balanced equation. The ratio is 2:1. So, 2 moles of NO react with 1 mole of O2.
a) For NO:
Given moles of NO = 0.0815 moles (initial moles)
The stoichiometric ratio indicates that 2 moles of NO react with 1 mole of O2. Therefore, the moles of O2 required (in order to react completely) = (0.0815 moles of NO) / (2 moles of NO/1 mole of O2) = 0.04075 moles of O2
b) For O2:
Given moles of O2 = 0.0789 moles (initial moles)
Since the calculated moles of O2 required (0.04075 moles) are less than the given moles of O2 (0.0789 moles), O2 is in excess, and NO is the limiting reagent.
2. Determine the moles of NO2 formed:
Since NO is the limiting reagent, its moles will be completely reacted according to the stoichiometric ratio of the equation.
Using the stoichiometric ratio of 2 moles of NO reacting to form 2 moles of NO2, we have:
moles of NO2 formed = (2 moles of NO) * (1 mole of NO2 / 2 moles of NO) = 1 mole of NO2
Thus, after the complete reaction, there will be 1 mole of NO2 formed.
3. Determine the moles of NO and O2 remaining after the reaction:
Since NO is the limiting reagent, it will be completely consumed in the reaction. Therefore, there will be no moles of NO remaining.
To find the moles of O2 remaining, we subtract the moles of O2 used in the reaction from the initial moles of O2:
moles of O2 remaining = (initial moles of O2) - (moles of O2 used)
= 0.0789 moles - 0.04075 moles
= 0.03815 moles
Thus, after the complete reaction, there will be 0 moles of NO remaining and 0.03815 moles of O2 remaining.
To summarize:
- Moles of NO after the complete reaction: 0 moles
- Moles of O2 after the complete reaction: 0.03815 moles
- Moles of NO2 formed after the complete reaction: 1 mole