Question

A nitrogen oxide is 63.65% by mass nitrogen. the molecular formula could be ________.

Answer 1

`N_(2)O`

Step-by-step explanation:

1. First suppose that the mass of the compound is 100g, so:

mass of N + mass of O = 100g

2. Multiply the percentages of N and O by the total mass of the compound:

For the N:

`63.65*100g=63.65g` of N

For the O:

`100-63.65=36.35g` of O

3. Divide the mass of each atom between the molar mass:

For the N:

`(63.65g)/(14g)=4.54`

For the O:

`(36.35g)/(16g)=2.27`

4. Divide each value by the smallest:

For the N:

`(4.54)/(2.27)=2`

For the O:

`(2.27)/(2.27)=1`

5. Write each atom with its number to obtain the molecular formula:

`N_(2)O`

Answer 2

To answer this question you need to know the molecular mass for both atoms. Nitrogen molecular mass is 14. Oxygen molecular mass is 16. If the 63.65% mass is nitrogen, then the 36.35% would be oxygen.

Then the ratio of nitrogen/oxygen would be: (63.65% /14) / (36.35% /14)= 4.53 /2.28 = 2
That mean there will be 2 nitrogen for every 1 oxygen. The molecular formula should be N2O