Molecular Mass

Q. The molecular mass of ${\text{SO}}_2$ is u.

1. 32
2. 48
3. 64

Q. Calculate the molar mass of Nitric acid ($HN{O}_3$).

Q.

The molecular mass of ${\text{NaHCO}}_3$ is

1. 66 u

2. 84 u

3. 107 u

4. 100 u

Q.

How many atoms of each element are there in $9.8g$ of sulphuric acid, ${\mathrm{H}}_2{\mathrm{SO}}_4$?(atomic mass, $\mathrm{H}=1,\mathrm{S}=32,\mathrm{O}=16$)

Q. Calculate the molecular masses of ${\text{H}}_2,{\text{O}}_2,{\text{CO}}_2,{\text{NH}}_3.$

Q.

Select the correct statements from the following.

1. Statement (i) is correct.

2. Statement (ii) is correct.

3. Statement (iii) is correct.

4. Statement (iv) is correct.

Q.

Which of the following weighs the least?
(a) 2 g atom of N (b) $3\times {10}^{25}$ atoms of carbon
(c) 1 mole fo sulphur (d) 7 g silver

Q.

An unknown gas shows a density of 3 g per litre at ${273}^{\circ }$ and 1140 mm Hg pressure. What is the gram molecular mass of this gas?

Q.

What is the mass of 100 molecules of sucrose?

1. 5.679 $\times {10}^{-22}$

2. 5.679 $\times {10}^{-20}$

3. 5.679 $\times {10}^{-21}$

4. 5.679 $\times {10}^{-23}$

Q.

The molecular mass of butane is

1. 58 u

2. 35 u

3. 56 u

4. 52 u

Q.

The molecular mass of hexane is 84 u.

1. True

2. False

Q.

A compound has the following percentage composition by mass: carbon 14.4%, hydrogen 1.2% and chlorine 84.5%. Determine the empirical formula of this compound. [H = 1;C=12;Cl = 35.5]

1. CHCl₂

2. CHCl

3. CHCl₄

4. CH₃Cl

Q.

Calculat the relative molecular masses of :
(a) Ammonium chloroplatinate$(N{H}_4{)}_{2}PtC{l}_6$
(b) Potassium chlorate,
(c) $CuS{O}_4.5H_{2}O,$
(d) $(N{H}_4{)}_{2}S{O}_4$ (e) $C{H}_{3}COONa,$ (f) $CHC{l}_3$
(g) $(N{H}_4{)}_{2}C{r}_2{O}_7$.

Q.

$112c{m}^3$ of a gaseous fluoride of phosphorus has a mass of 0.63 g. Calculate the relative molecular mass of the fluoride. If the molecule of the fluoride contains only one atom of phosphorus, then determine the formula of the phosphorus fluoride.
[F = 19; P = 31].

Q.

Which of the following would weight most
(a) 1 mole of $H_{2}O,$ (b) 1 mole fo $C{O}_2$,
(c) 1 mole of $N{H}_3$ (D) 1 mole fo CO?

Q.

Give three kinds of information conveyed by the formula $H_{2}O.$

Q.

Vapour density of a gas is 22. What is its molecular mass

1. 33

2. 22

3. 44

4. 11

Q. The number of gram molecules of oxygen in $6.02\times {10}^{24}CO$ molecules is :

1. $10$ gram molecules
2. $5$ gram molecules
3. $1$ gram molecules
4. $0.5$ gram molecules

Q.

A gas occupied $360c{m}^3$ at ${87}^{\circ }C$ and 380 mm Hg pressure. If the mass of gas is 0.546 g find its relative molecular mass.

Q. Calculate the molar mass of Nitric acid ($HN{O}_3$).

Q. Calculate the volume occupied by 3.5 g. of O_{​​​​​​2} gas at 27°C & 740 mm. press. [O = 16]

Q.

The molecular mass of ${\text{CaCl}}_2$ is :

1. 110u

2. 112u

3. 100u

4. 111u

Q.

Choose the correct answer.

The molecular mass of Potassium dihydrogen phosphate is ________________ .

1. 136

2. 140

3. 152

4. 135

Q. 16 gm of oxygen and 3 gm of hydrogen are mixed and kept at 760 mm pressure and 0 degree centigrade.the total volume occupied by mixture will be nearly??

Q.

${\mathrm{O}}_2$ is evolved by heating ${\mathrm{KClO}}_3$ using ${\mathrm{MnO}}_2$ as a catalyst
$2{\mathrm{KClO}}_3\to 2\mathrm{KCl}+3{\mathrm{O}}_2$

Calculate the volume occupied by $0.01$ mole of ${\mathrm{CO}}_2$ at STP.

Q. Calculate the formula unit masses of $ZnO,N{a}_{2}O,K_{2}C{O}_3$.
(atomic masses of $Zn=65u,Na=23u,K=39u,C=12u$ and $O=16u$)

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

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

Q.

Fill in the blanks:
(a) Molecular weight of a gas is twice its __________.
(b) Mass of 22.4 litre of a gas at STP is ___________.
(c) One gram atom of an element contains __________ atoms.
(d) One a.m.u. is the mass of __________ atom of C¹².
(e) Avogadro's number is equal to _________.

Q.

The molecular mass of ${\text{Na}}_2{\text{CO}}_3$ is 96 u.

1. 74

2. 51

Q. Real volume of the molecules of gas is ______ compared to the total volume of the gas.

1. equal
2. Cannot compare these quantities.
3. high
4. less