Molecular Mass

Q. Differentiate between molecular mass and formula unit mass.
[2 Marks]
[NCERT]

Q.

Molecular mass of ammonia is __ g.

Q.

What is the mass of 4.82 x ${10}^{25}$ molecules of $H_{2}O$ in grams?

___

Q. What is the molecular mass of the compound $S{O}_2$?

1. 64 u
2. 48 u
3. 32 u
4. 16 u

Q.

What is the mass percentage of hydrogen in the H₂O molecule?

1. 5.55%

2. 33.33%

3. 22.22%

4. 11.11%

Q.

The mass ratio of hydrogen to oxygen in water is :

1. 1:8

2. 8:1

3. 2:3

4. 3:2

Q.

The mass of a molecule of water is

1. $3\times {10}^{-26}kg$
2. $3\times {10}^{-25}kg$
3. $1.5\times {10}^{-26}kg$
4. $2.5\times {10}^{-26}kg$

Q. Which of the following is correct with respect to the mass ratio of the combining elements in the compound - $C_2{H}_{5}OH$?

1. Ratio of C:H:O is 8:3:12
2. Ratio of C:H:O is 2:6:1
3. Ratio of C:H:O is 6:2:1
4. Ratio of C:H:O is 12:3:8

Q. Calculate the molar mass of Calcium Hydroxide.

1. 65 g/mol
2. 84 g/mol
3. 74 g/mol
4. 100 g/mol

Q.

Molecular mass is defined as the

1. Mass of an atom compared with the mass of one molecule
2. Mass of an atom compared with the mass of an atom of Hydrogen
3. Mass of one molecule of any substance compared with the mass of an atom of C-12
4. Mass of an atom compared with the mass of an atom of Oxygen