Mole Concept

Q.

Calculate the molecular mass of:

Ammonium nitrate ${\mathrm{NH}}_4{\mathrm{NO}}_3$.

Q.

100 g of calcium carbonate on treatment with 73g of hydrochloric acid, produces carbon dioxide. What is the volume of carbon dioxide gas produced when the reaction is taking place at STP?

1. $11.2l$

2. $44.8l$

3. $5.6l$

4. $22.4l$

Q. 22.4 litres of helium gas is equivalent to its 1 mole.

1. True
2. False

Q. Calculate the number of moles present in 54 grams of aluminium sample. (Molar mass of aluminium is 27).

1. 2
2. 1
3. 0.5
4. Cannot be determined

Q.

$9.033\times {10}^{23}$ atoms of hydrogen is equal to:

1. 1.5 gm

2. 0.75 grams

3. 1.5 moles

4. 0.75 moles

Q.

Explain fractional atomic mass. What is the fractional mass of chlorine?

Q. The no. Of mole of oxygen in one litre of air containing 21%oxygen by volume under standard condition is 1)0.0093 mole 2)2.10 mole 3)0.186 mole 4)0.21 mole

Q.

How many moles of hydrogen atoms are present in 1 mole of $H_{2}O$?

1. 4

2. 1

3. 3

4. 2

Q.

Define Mole

Q. Which of the following compound has the highest mass?

1. 5 moles of ${\text{H}}_2\text{O}$
2. 12 moles of ${\text{CO}}_2$
3. 10 moles of ${\text{SO}}_2$
4. 13 moles of ${\text{NO}}_2$

Q. You are provided with two containers made up of $\left(A\right)$ copper and $\left(B\right)$ aluminium You are also provided with solution of (a) dilute $HCl$ (b) dilute $H{N}_3$ (c) $ZnC{l}_2$ and (d) $H_{2}O$. in which of the above containers these solutions are kept?

Q. Hydrolith has formula __________

Q.

Calculate the molar mass of Sulphur molecule, ${\mathrm{S}}_8$

Given the atomic masses of S = 32u

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

1. 1440.71 g
2. 1248.71 g
3. 1448.71 g
4. 1438.71 g

Q. Calculate the number of moles in
(i) $8g$ of oxygen atoms
(ii) $4.088\times {10}^{21}$ number of oxygen atoms (Atomic mass of $O=16u$)

Q. A drop of water is about $0.05$ $mL$. The density of water at room temperature is about $1.0$ $gm{L}^{-1}$. The number of water molecules present in a drop of water are:

1. $1.67\times {10}^{21}{H}_{2}O$ molecules
2. $1.67\times {10}^{26}{H}_{2}O$ molecules
3. $1.806\times {10}^{23}{H}_{2}O$ molecules
4. $1.806\times {10}^{21}{H}_{2}O$ molecules

Q. How many moles of electrons weight one kilogram?

1. $6.02\times {10}^{23}$
2. $\frac{1}{9.108}\times {10}^{31}$
3. $\frac{6.02}{9.108}\times {10}^{54}$
4. $\frac{1}{9.108\times 6.023}\times {10}^8$

Q. $3$ gm of Mg is burnt in a closed vessel containing $3$ gm of oxygen. The weight of excess reactant left is :

1. $1.0$ gm of oxygen
2. $0.5$gm of Mg
3. $0.5$ gm of oxygen
4. $1.0$ gm of Mg

Q. How many moles in $44gm$ of ${CO}_2$

Q.

How will you calculate the number of moles in a substance?

Q. When $x$ molecules are removed from $200mg$ of $N_{2}O,2.89\times {10}^{-3}$ moles of $N_{2}O$ are left $x$ will be:

1. ${10}^{20}$ molecules
2. ${10}^{-10}$ molecules
3. $21$ molecules
4. ${10}^{21}$ molecules.

Q.

Find the number of oxygen atoms in 88g of ${CO}_2$ ?

1. $2.4092\times {10}^{24}$

2. $2.4092\times {10}^{23}$ ​

3. $2409.2\times {10}^{24}$ ​

4. $24.092\times {10}^{24}$ ​

Q.

112cm³ of a gaseous fluoride of phosphorus has a mass of 0.63 g at STP. 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. $25.4$ g of iodine and $14.2$ g of chlorine are made to react completely to yield a mixture of $ICl$ and $IC{l}_3$. Calculate the number of moles of $ICl$ and $IC{l}_3$ formed.

1. 0.1 mole, 0.1 mole
2. 0.1 mole, 0.2 mole
3. 0.5 mole, 0.5 mole
4. 0.2 mole, 0.2 mole

Q. A mixture of $CO$ and $C{O}_2$ is found to have a density of $1.5g{L}^{-1}$ at ${30}^{\circ }C$ and $730torr$. What is the composition of the mixture?

Q. How much sugar $\left(C_{12}{H}_{22}{O}_{11}\right)$ will be required if each person on earth is given $100$ molecules of sugar? The population of the earth is $3\times {10}^{10}$.

1. $170.43\times {10}^{-10}g$
2. $170.43\times {10}^{-11}g$
3. $340.86\times {10}^{-11}g$
4. $340.86\times {10}^{-10}g$

Q. How many of the following species is/are equal to $0.05$ moles if its weight is $3$ g ?

Q. Which of the following statements is/ are correct?
I $5$ moles of $C{O}_2$ and $5$ moles of $H_{2}O$ have the same mass.
II $100g$ of $N{H}_3$ has more atoms than that present in $100g$ of $N_2$.
III $16g$ of solid sulphur contains $3.76\times {10}^{22}$ molecules/

1. I and II only
2. II and III only
3. III only
4. I only

Q.

Calculate the number of molecules in 1 kg of calcium chloride.

Q. The number of iron (Fe) atoms present in a pure sample of solid iron with a mass of 10 grams is equal to- (The atomic mass of iron is 55.9) .

1. $\frac{(6.02\times {10}^{23})}{\left(10.0\right)\left(55.9\right)}$
2. $\left(10.0\right)\times \left(55.9\right)\times (6.02\times {10}^{23})$ atoms
3. $\frac{\left(10.0\right)(6.02\times {10}^{23})}{\left(55.9\right)}$
4. $\frac{\left(10.0\right)}{\left(55.9\right)(6.02\times {10}^{23})}$
5. $\frac{\left(55.9\right)}{\left(10.0\right)(6.02\times {10}^{23})}$