One mole of carbon atoms has a mass of 12 g. Determine the number of atoms present in this sample:
(Given: Mass of \(C^{12}\) is $1.9926\times {10}^{-23}$ $g$)

1.	$1.2\times {10}^{23}$	2.	$6.022\times {10}^{22}$
3.	$12\times {10}^{22}$	4.	$6.022\times {10}^{23}$

Which of the following contains the maximum number of atoms ?

An aqueous solution of NaOH has a molarity of 2 M and a density of 1.28 g cm⁻³.
Calculate the molality of the solution:
[Given: Molecular mass of NaOH = 40 g mol^-1]

The volume of oxygen gas (O₂) needed to completely burn 1 L of propane gas (C₃H₈)  (both O₂ & propane measured at 0°C and 1 atm) will be:
1. 7 L
2. 6 L
3. 5 L
4. 10 L

The volume occupied by one water molecule (density = 1 g cm^-3) is:

1. $9.0\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

2. $6.023\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

3. $3.0\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

4. $5.5\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

10 g of hydrogen and 64 of oxygen were filled in a steel vessel and exploded. The amount of water produced in this reaction will be:

1. 2 mol

2. 3 mol

3. 4 mol

4. 1 mol

Mole fraction of solute in a 1.00 molal aqueous solution is:
1.  0.0177
2.  0.0344
3.  1.770
4.  0.1770