Which of the following is dependent on temperature?

1.	Molarity	2.	Mole fraction
3.	Weight percentage	4.	Molality

A mixture containing 2.3 g of formic acid (HCOOH) and 4.5 g of oxalic acid (H₂C₂O₄) is
heated with concentrated H₂SO₄. The gases evolved are passed through KOH pellets.

Calculate the mass of the gas that remains unabsorbed by KOH.

1.  1.4

2.  3.0

3.  2.8

4.  4.4

A 20.0 g impure sample of magnesium carbonate is heated completely and produces 8.0 g of magnesium oxide along with carbon dioxide.
Given: Atomic mass of Mg = 24
What is the percentage purity of MgCO₃ in the sample?

A mixture consists of hydrogen and oxygen gases in the mass ratio 1 : 4. Determine the mole ratio of hydrogen molecules to oxygen molecules present in the mixture.

25.3 g of sodium carbonate, Na₂CO₃, is dissolved in enough water to make 250 mL of a solution. If sodium carbonate completely dissociates, the molar concentrations of sodium ion, Na⁺ and carbonate ion, $C{O}_3^{2-}$are respectively:
(molar mass of Na₂CO₃ = 106g mol^-1)

1. 0.955 M and 1.910 M
2. 1.910 M and 0.955 M
3. 1.90 M and 1.910 M
4. 0.477 M and 0.477 M

Which of the following represents the volume occupied by a single water molecule, assuming the density of water is \(1\,\text{g cm}^{-3}\)?

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

2. $\mathrm{ 6}.023\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

3. $\mathrm{ 3}.0\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

4. $\mathrm{ 5}.5\times {10}^{-23}$ $$ ${\mathrm{cm}}^3$

What volume of oxygen gas is required for the complete combustion of 1 L of propane gas, C₃H₈, when both gases are measured at 0°C and 1 atm?
1. 7 L
2. 6 L
3. 5 L
4. 10 L

An organic compound contains carbon, hydrogen, and oxygen. If elemental analysis reveals 38.71% carbon and 9.67% hydrogen, which of the following is its empirical formula?

What is the number of moles of PbCl₂ formed when 6.5 g of PbO reacts with 3.2 g of HCl?

1. 0.044
2. 0.333
3. 0.011
4. 0.029