May 16 & 17 SL P1A

Which equation represents sublimation?

• 2Al (s) + 3I2 (g) → 2AlI3 (s)

• HgCl2 (s) → HgCl2 (g)

• I2 (g) → I2 (s)

• CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + CO2 (g) + H2 O (l)

For which compound is the empirical formula the same as the molecular formula?

Ar (H) = 1; Ar (C) = 12; Ar (O) = 16

• A

• B

• C

• D

Which compound has the greatest percentage by mass of nitrogen atoms?

• N₂H₄

• NH₃

• N₂O₄

• NaNO₃

Which statements about mixtures are correct?

I. The components may be elements or compounds.

II. All components must be in the same phase.

III. The components retain their individual properties.

• I and II only

• I and III only

• II and III only

• I, II and III

In which mixture is NaOH the limiting reagent?

• 0.20 mol NaOH + 0.10 mol H2 SO

• 0.10 mol NaOH + 0.10 mol H2 SO4

• 0.20 mol NaOH + 0.10 mol HNO3

• 0.10 mol NaOH + 0.10 mol HNO

5.0 cm³ of 2.00 mol dm⁻³ sodium carbonate solution, Na₂CO₃(aq), was added to a volumetric flask and the volume was made up to 500 cm³ with water. What is the concentration, in mol dm⁻³, of the solution?

• 0.0050

• 0.0040

• 0.020

• 0.010

What is the expression for the volume of hydrogen gas, in dm³, produced at STP when 0.30 g of magnesium reacts with excess hydrochloric acid solution?

Mg(s) + 2HCl(aq) --> MgCl2(aq) + H2(g)

(Molar volume of an ideal gas at STP = 22.7 dm³mol⁻¹)

• 0.30 × 2 × 22.7 / 24.31

• 0.30 × 22.7 / 24.31

• 0.30 × 24.31 / 22.7

• 0.30 × 22.7 / (24.31 × 2)

Why do gases deviate from the ideal gas law at high pressures?

• Molecules have finite volume.

• Cohesive forces increase the volume from the idea

• Increasing pressure increases the temperature of the gas.

• Collisions between molecules occur more frequently as pressure increases.

In which set do all the species contain more electrons than neutrons?

• 14N, 16O, 11C

• 14N, 16O, 11C^4-

• 14N^3-, 16O^2-, 11C

• 14N^3-, 16O^2-, 11C^4+

Which electron transition in the hydrogen atom emission spectrum emits radiation with the longest wavelength?

• n = 2 → n = 1

• n = 1 → n = 2

• n = 4 → n = 1

• n = 3 → n = 2