Mole

Q. What is the number of oxygen atoms present in 5 moles of sulphuric acid $\left(H_{2}S{O}_4\right)$?

1. $120.44\times {10}^{23}$
2. $90.33\times {10}^{23}$
3. $60.22\times {10}^{23}$
4. $75.55\times {10}^{23}$

Q.

What is the molecular mass of methane (CH₄) ?

1. 16 u
2. 12 u
3. 20 u
4. 24 u

Q. If the mass of a single atom of an element is $5.31\times {10}^{-23}$ g, then which amongst the following elements could it be?

1. Potassium
2. Sulphur
3. Nitrogen
4. Oxygen

Q. The formula unit mass of $N{a}_{2}O$ is ____.

1. 50
2. 52
3. 62
4. 48

Q.

Which of the following is the best definition of a mole?

1. A mole of any substance contains the same number as 12g of12c

2. Amole of any substance contains the same number of particles as 12 g of naturally occuring carbon

3. A mole is 6.02x10 ²³ atoms of any substance

4. A mole is 12g of any element

Q. One mole of $H_{2}O$ contains moles of hydrogen atoms.

1. four
2. three
3. two
4. one

Q. What are the number of moles and the number of H atoms present in $9.033\times {10}^{23}$ molecules of water?

1. $18.066\times {10}^{23}$ atoms, 3 moles
2. $24.088\times {10}^{23}$ atoms, 4 moles
3. $2.8066\times {10}^{24}$ atoms, 3 moles
4. $5.419\times {10}^{24}$ atoms, 9 moles

Q.

A beaker contains $6.02\times {10}^{24}$ molecules of water . How many mole of atoms is this?

1. 30X6.02X10²⁴

2. 1

3. 30

4. 10

Q.

If one mole of carbon atoms weighs 12grams, what is the mass (in grams) of 1 atom of carbon?

Q.

If 1 gram of Carbon contains x atoms, what will be the number of atoms in 1 gram of Magnesium ?

Q. How many moles of hydrogen atoms are present in one mole of water?

1. one
2. two
3. three
4. four

Q.

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

1. 4.5

2. 18

3. 9

4. 6

Q.

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

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

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

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

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

Q.

Comment: "A mole of carbon atoms".

Q. The number of gram-molecules of oxygen in $6.022\times {10}^{24}$ molecules of $CO$ is:

1. $5$ gm moles
2. $10$ gm moles
3. $0.5$ gm mole
4. $1$ gm mole

Q. How many moles of hydrogen atoms are present in one mole of water?

1. one
2. four
3. two
4. three

Q. One mole of a substance contains the same number of particles as the number of atoms present in 12 g of carbon-12.

1. False
2. True

Q. The number of atoms in $0.004$ g of Mg will be:

1. $4\times {10}^{20}$
2. $8\times {10}^{20}$
3. $6.02\times {10}^{20}$
4. ${10}^{20}$

Q. Which one of the following is not the same number as the rest?

1. The number of hydrogen atoms in 2 moles of $H_{2}O$
2. The number of molecules in 4 moles $C{O}_2$
3. The number of chloride ions in 4 moles of $CaC{l}_2$
4. The number of hydrogen atoms in $\frac{1}{2}$ mole of $C_3{H}_8$

Q. The total number of atoms present in $1$ mole of potash alum, in terms of Avogadro number $N_A$, is:

1. $3N_A$
2. $5N_A$
3. $8N_A$
4. $32N_A$

Q. The number of atoms in 0.1 mole of a tetra atomic gas is:

1. $2.4\times {10}^{22}$
2. $6.026\times {10}^{22}$
3. $2.4\times {10}^{23}$
4. $3.600\times {10}^{23}$

Q. How many moles of ammonia weigh 85 g?

1. 5 moles
2. 15 moles
3. 10 moles
4. 20 moles

Q. If the mass of a single atom of an element is $5.31\times {10}^{-23}$ g, then which amongst the following elements could it be?

1. Oxygen
2. Potassium
3. Sulphur
4. Nitrogen

Q. The number of potassium atoms present in $117$ g of potassium sample (Molecular Weight $=39$ g/mole) is:

1. $9\times 6.023\times {10}^{23}$ atoms
2. $7\times 6.023\times {10}^{23}$ atoms
3. $4\times 6.023\times {10}^{23}$ atoms
4. $3\times 6.023\times {10}^{23}$ atoms

Q. One mole of $H_{2}O$ contains moles of hydrogen atoms.

1. one
2. two
3. three
4. four

Q. Question 43
A sample of ethane $\left(C_2{H}_6\right)$ gas has the same mass as $1.5\times {10}^{20}$ molecules of methane $\left(C{H}_4\right)$. How many $C_2{H}_6$ molecules does the sample of gas contain?

Q. 34 g of $H_{2}O$ decomposes to give g of hydrogen and g of oxygen.

1. 3.78
2. 30.22
3. 4.23
4. 32.22

Q.

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

1. 18

2. 4.5

3. 6

4. 9

Q. Calculate the molecular mass of water.

1. 18

Q. Which have same number of atoms $16$ of $O_2$, $4$ of Hydrogen, $44$ of $C{O}_2$, $28$ of Nitrogen and $32$ of $O_2$