Question

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

Answer 1

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

Answer 2

Answer:

$N_{2}O$

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:

$\frac{63.65g}{14g}=4.54$

For the O:

$\frac{36.35g}{16g}=2.27$

4. Divide each value by the smallest:

For the N:

$\frac{4.54}{2.27}=2$

For the O:

$\frac{2.27}{2.27}=1$

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

$N_{2}O$