By dividing the percentage composition with the molar mass of that element we will get the empirical formula. Then using that empirical formula and formula mass we can find the molecular formula.
<u>Explanation:</u>
The chemical properties of any substance are defined obviously by the different types and relative amounts of atoms constituting its primary entities (in case of covalent compounds the primary entities are molecules and ions in the event of ionic compounds).
A percent composition of any compound gives the mass percent of each element present in the compound; in addition to that frequently it is determined experimentally and utilized to derive an empirical formula of any compound. An empirical formula mass of any covalent compound could be comparable with the molar or molecular mass of a compound to acquire a molecular formula.
<span>Chemical formula of ammonia = NH3
As we can see there are three atoms of hydrogen in one molecule of ammonia.
So in the 200 molecule of ammonia there will be = 200*3 = 600 atoms of hydrogen.
Answer - 600 atoms of hydrogen.</span>
Answer : The mass of
occupy 30.3 L under the same conditions will be, 24.9 grams.
Explanation :
First we have to calculate the moles of 

Now we have to calculate the moles of
in 30.3 L by using Avogadro's law.
Avogadro's law : It is defined as the volume of gas is directly proportional to the number of moles of gas at constant pressure and temperature.

or,

where,
= initial volume of gas = 6.21 L
= final volume of gas = 30.3 L
= initial moles of gas = 0.16 mol
= final temperature of gas = ?
Now put all the given values in the above equation, we get:


Now we have to calculate the mass of 

Molar mass of
= 32 g/mol

Therefore, the mass of
occupy 30.3 L under the same conditions will be, 24.9 grams.