Question

If the mass percentage of nitrogen in a compound is 10% and there are two nitrogen atoms in a molecule of the
compound, the molecular weight of the compound is ______ u (round off to the nearest whole number)

Answer 1

Answer:

280 u

Explanation:

Atomic mass of nitrogen = 14.(approx)

so, mass of Nitrogen in 1 molecule of the compound = 14 × 2 = 28

(given - the %age of nitrogen is 10 %)

so the mass of compound = 28 × 100/10 = 280 u

hope it helps :)

Answer 2

Given: The mass percentage of nitrogen in a compound is 10% and there are two nitrogen atoms in a molecule of the compound.

To find: We have to find out the molecular weight of the compound.

Solution:

The atomic mass of nitrogen is 14.

There are two nitrogen atoms in a molecule of the compound.

So, mass of nitrogen is 14×2=28.

Now mass percent is a ratio of mass of nitrogen to total molecular weight of the compound multiplied by 100.

Now mass percentage is 10%.

Let molecular weight of the compound is x.

So, we can write

$\frac{10}{100} = \frac{28}{x} \\ x = 280$

The molecular weight of the compound is 280u.