Nitrogen forms more oxides than any other element. The percents by mass of N in three different nitrogen oxides are (I) 46.69%; (II) 36.85%; (III) 25.94%. For each compound, determine (a) the simplest whole-number ratio of N to O, and (b) the number of grams of oxygen per 1.00 g of nitrogen.

[1]. NO;        1.14 g,

[2]. N₂O₃;    1.71 g,

[3]. N₂O₅;    2.86 g.

Explanation:

[1]. For the first oxide, there is 46.69% of Nitrogen and [100 - 46.69%] of Oxygen, that is 53.31% of oxygen. The simplest whole-number ratio of N to O = [46.69/14.01] ÷ [53.31/ 16] = 3.33/3.33 = 1 : 1.

Hence, Nitrogen =1 and oxygen is 1, the compound = NO.

The number of grams of oxygen per 1.00 g of nitrogen for this compound is calculated as below:  

The number of grams of oxygen per 1.00 g of nitrogen for this compound = (1/ 0.4669) - 1 = 2.14 - 1 = 1.14 g.

[2]. For the second oxide, there is  36.85% of Nitrogen and [100 -  36.85%] of Oxygen, that is 63.15% of oxygen. The simplest whole-number ratio of N to O = [36.85/14.01] ÷ [63.15/ 16] = 2.63/3.94 = 1 : 1.5.

Hence, Nitrogen =1 and oxygen is 1.5. There is need to change it to whole number, therefore, when it is multiplied by 2, it gives 2:3. Therefore, the compound = N₂O₃.

The number of grams of oxygen per 1.00 g of nitrogen for this compound is calculated as below:  

The number of grams of oxygen per 1.00 g of nitrogen for this compound = (1/ 0.3685) - 1 = 2.71 - 1 = 1.71 g.

(3). For the third oxide, there is 25.94% of Nitrogen and [100 -  25.94%] of Oxygen, that is 74.06% of oxygen. The simplest whole-number ratio of N to O = [25.94/14.01] ÷ [74.06/ 16] = 1.85/4.63= 1 : 2.5.

Hence, Nitrogen =1 and oxygen is 2.5. There is need to change it to whole number, therefore, when it is multiplied by 2, it gives 2:3. Therefore, the compound = N₂O₅.

The number of grams of oxygen per 1.00 g of nitrogen for this compound is calculated as below:  

The number of grams of oxygen per 1.00 g of nitrogen for this compound = (1/ 0.2594) - 1 = 3.86 - 1 = 2.86 g