## General Chemistry

### Matter

Question
10 out of 14

A student researcher analyzing the identity of the by-product of a reaction found that the compound contained 63.6% nitrogen and 36.4% oxygen. What is the most likely formula of this compound?

 A NO B NO2 C N2O D N2O3
Ans. C In the question, the percentage compositions of nitrogen and oxygen are given. With that information, we have to find the formula of that compound. Just as discussed in our review, assume that we have 100 grams of this compound. If there are 100 grams, logically it should contain 63.6 grams of nitrogen and 36.4 grams of oxygen.

Step 1

# of moles of nitrogen = 63.6/14 4.5 moles of nitrogen

# of moles of oxygen = 36.4/16 2.275 moles of oxygen

Step 2

Divide every number of moles with the smallest number of moles calculated in Step 1. Here the smaller one is 2.275. Divide both mole numbers by 2.275. This will give you the simplest ratio between them.

Nitrogen 4.5/2.275 2 Oxygen 2.275/2.275 1

Since the ratio of nitrogen to oxygen is 2:1, the compound is N2O.