Question

Find the molecular weight of the following compound
a) HNO³ b)NaOH c) H²SO⁴​

Answer 1

Answer:

(a) 63 u.

(b) 40 u.

(c) 98 u.

Step-by-step explanation:

(a) HNO₃

We know,

Atomic weight of Hydrogen is 1 u.

Atomic weight of Nitrogen is 14 u.

Atomic weight of Oxygen is 16 u.

Molecular weight of HNO₃ which contains one atom of hydrogen, one atom of nitrogen and three atoms of oxygen :

= 1 + 14 + (16 × 3)

= 15 + 48

= 63

Thus,

Molecular weight of HNO₃ is 63 u.

(b) NaOH

We know,

Atomic weight of Sodium is 23 u.

Atomic weight of Oxygen is 16 u.

Atomic weight of Hydrogen is 1 u.

Molecular weight of NaOH which contains one atom of Sodium, one atom of Oxygen and one atom of hydrogen :

= 23 + 16 + 1

= 40

Thus,

Molecular weight of NaOH is 40 u.

(c) H₂SO₄

We know,

Atomic weight of Hydrogen is 1 u.

Atomic weight of Sulphur is 32 u .

Atomic weight of Oxygen is 16 u .

Molecular weight of H₂SO₄ which contains two atoms of hydrogen, one atom of sulphur and four atoms of oxygen :

= (1 × 2) + 32 + (16 × 4)

= 2 + 32 + 64

= 98

Thus,

Molecular weight of H₂SO₄ is 98 u.

Answer 2

a) HNO₃ :

Atomic Weight of

Hydrogen is 1 u

Nitrogen is 14 u

Oxygen is 16 u

so,

Molecular mass of HNO₃

= 1(1) + (14)(1) + (16)(3)

= 1 + 14 + 48

= 63 u

Molecular Mass of HNO₃ = 63 u

b) NaOH

Atomic Weight of

Sodium is 23 u

Oxygen is 16 u

Hydrogen is 1 u

so,

Molecular Mass of NaOH

= (23)(1) + (16)(1) + (1)(1)

= 23 + 16 + 1

= 40 u

Molecular Mass of NaOH = 40 u

c) H₂SO₄

Atomic Weight of

Hydrogen is 1 u

Sulphur is 32 u

Oxygen is 16 u

so,

Molecular Mass of H₂SO₄

= (1)(2) + (32)(1) + (16)(4)

= 2 + 32 + 64

= 98 u

Molecular Mass of H₂SO₄ = 98 u