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]

1.	1.20 m	2.	1.56 m
3.	1.67 m	4.	1.32 m

If 2.74 g of the metal oxide contains 1.53 g of metal, then the empirical formula of vanadium oxide is:

(Atomic Mass of V = 52)

1. ${\mathrm{V}}_2{\mathrm{O}}_3$

2. $\mathrm{VO}$

3. ${\mathrm{V}}_2{\mathrm{O}}_5$

4. ${\mathrm{V}}_2{\mathrm{O}}_7$

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

10 g of hydrogen and 64 g 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

If Avogadro number \(N_{A}\), is changed from$\mathrm{}$ \(6 . 022 \times \left(10\right)^{23}\)\(\text{mol}^{- 1}\) to \(6 . 022 \times \left(10\right)^{20} ~\text{mol}^{- 1}\) this would change the:

Which of the following contains the maximum number of atoms ?

An oxide of iron contains 69.9% iron and 30.1% oxygen by mass. What is its empirical formula?

1. FeO

2. Fe₂O₃

3. Fe₃O₄

4. Fe₃O₂

If the density of the solution is 3.12 g ml^-1, then what will be the mass of the 1.5 ml solution in two significant figures?

Match the following physical quantities with units.

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