Mole

Q.

Calculate the number of molecules of sulphur (${\mathrm{S}}_8$) present in $16\mathrm{g}$ of solid sulphur.

Q.

$2$ Moles of nitrogen atoms at NTP occupy a volume of :

1. $56\mathrm{L}$

2. $22.4\mathrm{L}$

3. $11.2\mathrm{L}$

4. $44.8\mathrm{L}$

Q. Calculate the number of electrons present in 60 g of water.

Q.

Which among the following statement is incorrect?

1. One gram atom of carbon contains avogadro’s number of atoms.

2. One mole of oxygen gas contains avogadro’s number of atoms.

3. One mole of hydrogen contains avogadro’s number of atoms.

4. Mole = Mass / Molecular mass.

Q.

How many moles of oxygen atoms are present in one mole of the following compounds $\mathbf{\left(}{\mathbf{Cl}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{7}}\mathbf{\right)}$?

Q.

One mole of oxygen molecule have

1. Avogadro Number

2. 1 GMM

3. 1 GAM

4. All of the above.

Q. When magnesium metal is added to water, hydrogen gas, ${\text{H}}_2$ is released. If 72 g of hydrogen gas is liberated in this reaction, how many number of moles of hydrogen gas is produced?
$\text{Mg}$ (s) + $\text{2}$${\text{H}}_2\text{O}$ (l) $\to$ $\text{Mg}{\text{(OH)}}_2$ (aq) + ${\text{H}}_2$ (g) ​

Q.

Which of the following formulae is/are correct to calculate the number of moles?

1. Number of moles of atoms = $\frac{\text{Mass in gram}}{\text{Gram atomic mass}}$

2. Number of moles of molecules = $\frac{\text{Mass in gram}}{\text{Gram molecular mass}}$

3. Number of moles = $\text{Number of particles}\times \text{Avogadro number}$

4. Number of moles of gas at STP = $\frac{\text{Volume in STP (litre)}}{\text{22.4 L}}$

Q. An enzyme contains $5.6\%$ Fe, Calculate the number of Fe atoms present in $1g$ of the enzyme.

1. $12.044\times {10}^{20}$
   
2. $6.022\times {10}^{20}$
   
3. $6.022\times {10}^{21}$
4. none of these

Q. A number of moles of oxygen present in 0.3 moles of oxalic acid dihydrate $(COOH{)}_2.2H_{2}O$ are:

1. $18$
2. $0.9$
3. $1.8$
4. $9$

Q. Number of atoms (in $N_A$) of hydrogen in $67.2$ L of $H_2$ at $STP$, is:

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

1. 10 g molecules
2. 0.5 g molecules
3. 1 g molecule
4. 5 g molecule

Q.

Which has a maximum number of molecules?

1. 1 g of ${\mathrm{CO}}_2$

2. 1 g of ${\mathrm{N}}_2$

3. 1 g of ${\mathrm{CH}}_4$.

4. 1 g of ${\mathrm{H}}_2$

Q.

The number of moles of molecules present in 288 g of oxygen gas is:

1. 18

2. 9

3. 36

4. 2

Q. The number of oxygen atoms in 6.4 g of oxygen are :

1. $6.023\times {10}^{22}$
2. $1.2046\times {10}^{23}$
3. $6.023\times {10}^{23}$
4. $1.2046\times {10}^{22}$

Q.

How many moles of hydrogen atoms are present in 1 mole of ${\text{H}}_2\text{O}$?

1. 1

2. 4

3. 3

4. 2

Q. The number of $g$ molecules of oxygen in $6.023\times {10}^{24}CO$ molecules is ________________.

1. $1g$ molecule
2. $0.5g$ molecule
3. $5g$ molecules
4. $10g$ molecules

Q. One mole of a substance contains $6.022\times {10}^{23}$ particles.

1. False
2. True

Q.

23 October is celebrated as

1. International molecule day

2. International Avogadro day

3. International atom day

4. International mole day

Q. $1g$ molecule of $V_2{O}_5$ contains

1. $5$ mole of oxygen atom
2. $2$ mole of $V$ atom
3. $2.5$ mole of oxygen atom
4. $1$ mole of oxygen atom

Q. Wt. of $50$ atoms of an element is $3000amu$. Calculate no. atoms in $240gm$ of element.

Q.

Give the SI unit of mole.

Q.

Which of the following formulae is/are correct to calculate the number of moles?

1. Number of moles of atoms = $\frac{\text{Mass in gram}}{\text{Gram atomic mass}}$

2. Number of moles of molecules = $\frac{\text{Mass in gram}}{\text{Gram molecular mass}}$

3. Number of moles = $\text{Number of particles}\times \text{Avogadro number}$

4. Number of moles of gas at STP = $\frac{\text{Volume in STP (litre)}}{\text{22.4 L}}$