Question

Calculate the mass percentage of oxygen present in HNO3..( Mass of H=1u; N=14u; O=16u )

Answer 1

MASS PERCENTAGE OF OXYGEN

Given us the compound,

HNO₃

We have,

• H = 1 g
• N = 14 g
• O = 16 g

First, Let us find the mass of the compound by adding the mass of each elements.

⇒ 1 × 1 + 1 × 14 + 3 × 16

⇒ 1 + 14 + 48

⇒ 63 g

Now, Let us find the mass of oxygen present in the compound.

⇒ 3 × Molar mass of Oxygen

⇒ 3 × 16

⇒ 48 g

The mass percentage is given as,

⇒ Mass of Element in that Compound / Mass of compound × 100

⇒ Mass of Oxygen / Mass of compound × 100

⇒ 48 / 63 × 100

⇒ 0.76 × 100

⇒ 76 %

Hence, The mass percentage of oxygen in HNO₃ is 76%

Some Information :-

☞ ppm can be calculated as:

Mass of solute / Mass of solution × 10⁶

☞ ppb can be calculated as:

Mass of solute / Mass of solution × 10⁹

Answer 2

$\mathcal{\green{\underline{\red{GIVEN:}}}}$

We are given a compound HNO₃

• H = 1 g
• N = 14 g
• O = 16 g

$\mathcal{\green{\underline{\red{TO \:\: FIND:}}}}$

The mass percentage of oxygen.

$\mathcal{\green{\underline{\red{SOLUTION:}}}}$

Find the molar mass of the molecule.

$\implies \sf HNO_3$

Substitute the values of the masses of the atoms.

$\implies 1 \times 1 + 1 \times 14 + 3 \times 16$

(Remember, O₃ means O×3)

$\implies\boxed{\sf{\blue{63g}}}$

Find the mass of oxygen in the compound.

$\sf HN\underline{O_3}$

$\sf \implies 3 \times Molar \ mass \ of \ Oxygen$

$\sf \implies 3 \times 16$

$\implies \boxed{\sf{\blue{48g}}}$

The mass percentage of a molecule is given as,

$\boxed{\sf{\blue{\dfrac{Mass \ of \ Element \ in \ that \ Compound }{ Mass of compound} \times 100}}}$

Here, the mass of the element in that compound would be mass of oxygen.

$\sf \dfrac{48}{63} \times 100$

$\implies \boxed{\boxed{76 \%}}$

∴THE MASS% OF O₂ IN HNO₃ is 76%