3.2.3.1 Trends in physical properties [of the halogens]

Which statement is correct about the reaction between concentrated sulfuric acid and solid sodium bromide?

• Bromide ions are reduced.

• Hydrogen bromide and sulfur are formed.

• Sulfuric acid acts as an oxidising agent.

• Bromine and hydrogen sulfide are formed.

Which is the best technique to remove the silver chloride that forms when aqueous solutions of silver nitrate and sodium chloride react?

• Refluxing

• Evaporation

• Filtration

• Distillation

Which statement about astatine is correct?

• Astatine has a greater electronegativity than bromine

• Astatine is a better oxidising agent than bromine

• Astatine has a greater boiling point than bromine

• Astatine has a greater first ionisation energy than bromine

Which species is not produced by a redox reaction between solid sodium iodide and concentrated sulfuric acid?

• Na₂SO₄

• H₂S

• S

• SO₂

Which equation represents a reaction that does take place?

• Cl₂ + 2NaI ⟶ 2NaCl + I₂

• Br₂ + 2NaCl ⟶ 2NaBr + Cl₂

• NaCl + H₂O ⟶ HCl + NaOH

• 2HCl + H₂SO₄ ⟶ Cl₂ + SO₂ + 2H₂O

Which species is the best oxidising agent?

• Cl₂

• Cl⁻

• Br ₂

• Br⁻

Which of these substances reacts most rapidly to produce a silver halide precipitate with acidified silver nitrate?

• CH₃Br

• CH₃Cl

• CH₃F

• CH₃l

The boiling points of the halogens increase down Group VII because

• covalent bond strengths increase.

• bond polarities increase.

• the surface areas of the molecules increase.

• electronegativities increase.

An aqueous solution of a sodium salt gave no precipitate when treated with either silver nitrate solution or barium chloride solution. Which one of the following could be the formula of the sodium salt?

• NaI

• Na₂SO₄

• NaBr

• NaF

On heating, magnesium reacts vigorously with element X to produce compound Y. An aqueous solution of Y, when treated with aqueous silver nitrate, gives a white precipitate that is readily soluble in dilute aqueous ammonia. What is the minimum mass of X that is needed to react completely with 4.05 g of magnesium?

• 11.83 g

• 5.92 g

• 5.33 g

• 2.67 g