MCQs

One formula unit produces 5 ions (2 Al³⁺ + 3 SO₄²⁻). Therefore, 0.1 mol gives 0.5 mol ions = 3.011 × 10²³ ions.

Moles of CS₂ = 19/76 = 0.25 mol. According to the equation, 1 mol CS₂ produces 2 mol SO₂. Therefore, 0.25 mol CS₂ forms 0.5 mol SO₂. Mass = 0.5 × 64 = 32 g.

Twenty-five grams equal 0.25 mole CaCO₃. The same amount of CO₂ occupies 5.6 dm³ at STP.

1.6 g oxygen equals 0.05 mole. Therefore, the number of molecules equals 0.05 × Avogadro's number.

One mole Pb(NO₃)₂ forms one mole PbO whose molar mass is 223 g.

Each mole KMnO₄ contains four moles oxygen atoms. Therefore, 0.25 mole contains one mole oxygen atoms.

Iron provides only 0.5 mole while sulfur provides 0.625 mole. Iron is present in the smaller stoichiometric amount.

Multiplication by Avogadro's number gives approximately 56 g mol⁻¹, the atomic mass of iron.

One mole pentane forms eleven moles of gaseous products. One-quarter mole forms 2.75 moles.

Gas volumes follow mole ratios. Hydrogen volume is three times nitrogen volume.

Molecular formula becomes C₆H₁₂O₆, containing twelve hydrogen atoms.

Twelve moles of water react with one mole Al₄C₃. Twelve × 18 = 216 g.

One mole methane requires two moles oxygen. Therefore, oxygen required is 64 g.

Benzene contains six carbon atoms per molecule.

Equal coefficients indicate equal numbers of moles.

Ten grams correspond to 0.1 mole CaCO₃, producing 0.1 mole CO₂ occupying 2.24 dm³ at STP.

The sample contains 0.25 mole urea. With molar mass 60 g mol⁻¹, the mass equals 15 g.

One mole H₂S produces 1.5 moles sulfur. The mass becomes 1.5 × 32 = 48 g.

Every molecule contains four chlorine atoms. Therefore, 0.5 mole CCl₄ contains 2 moles of chlorine atoms.