In what order does the reducing power of the hydrogen halides increase?

• HCl < HBr < HI
• HBr < HI < HCl
• HCl < HI < HBr
• HI < HBr < HCl

Which of the following is NOT a correct statement about iodine?

• A crystal of iodine contains covalent bonds and van der Waals' forces
• The first ionisation energy of iodine is less than that of bromine
• Iodine vapour is purple
• The hydride of iodine is greater thermal stability than that of bromine

Which properties in the sequence hydrogen chloride, hydrogen bromide and hydrogen iodide steadily increase?

• thermal stability
• ease of of oxidation
• bond length

What happens when chlorine is bubbled through aqueous potassium iodide?

• Chlorine is oxidised to chlorate(V) ions
• Iodide ions are oxidised to iodine
• Chlorine is oxidised to chloride ions
• Iodide ions are reduced to iodine

What trend is observed on descending Group VII?

• The colours of the elements become lighter
• The hydrides of the elements become more thermally stable
• The elements become more volatile
• The reacions of the elements with hydrogen become less vigorous

What happens when bromine solution is added to a solution of sodium iodide?

• A reaction occurs without changes in oxidation state
• Bromine atoms are reduced, iodide ions are oxidised
• Bromine atoms are oxidised, ioded ions are reduced
• No rection occurs

Cl₂ gas reacts with KBr. Which balanced equation and color change is correct?

• Cl₂(g) + KBr(aq) → KCl(aq) + Br(l); Colorless to orange
• Cl₂(g) + 2KBr(aq) → 2KCl(aq)+ Br₂(l); Colorless to orange
• Cl₂(g) + 2KBr(aq) → 2KCl(aq)+ Br₂(l); Colorless to yellow
• Cl₂(g) + 2KBr(aq) → 2KCl(aq)+ Br₂(l); Colorless to brown

Chlorine is a strong enough oxidizing agent to oxidize both bromide and iodide ions.

True or False: Fluorine (F₂) is expected to have weaker van der Waals forces than iodine (I₂).

As you go down Group 17 (the halogens), the elements become more volatile.

Which of the following trends is observed as you go down Group VII (halogens)?

• A) Atomic radius decreases, electronegativity increases
• B) Electronegativity decreases, volatility decreases
• C) Bond enthalpy increases, volatility decreases
• D) Volatility increases, atomic radius decreases

Why is fluorine considered the most powerful oxidizing agent among halogens?

• A) It has the highest atomic radius.
• B) Its bond enthalpy is very low.
• C) The repulsion between lone pairs reduces the energy required to break its bond.
• D) It has the highest electronegativity.

What happens when chlorine reacts with cold aqueous sodium hydroxide?

• A) It forms NaCl and NaClO3.
• B) It undergoes reduction but not oxidation.
• C) It forms NaCl, NaClO, and water.
• D) It forms NaCl and oxygen gas.

Which halogen is least likely to displace iodide ions from an aqueous solution of potassium iodide?

• A) Fluorine
• B) Chlorine
• C) Bromine
• D) Iodine

When bromine reacts with sodium thiosulfate in the presence of water, what is formed?

• A) Sodium tetrathionate (N2S4O6)
• B) Sodium sulfate (Na2SO4)
• C) Sodium bromate (NaBr)
• D) Sodium chloride (NaCl)

What is the product when iodine reacts with sodium thiosulfate?

• A) Sodium sulfate (Na2SO4)
• B) Sodium tetrathionate (Na2S4O6)
• C) Sodium iodate (NaIO3)
• D) Sodium chloride (NaCl)

Which of the following statements about the use of halogens in industrial applications is true?

• A) CFCs are now used extensively as refrigerants due to their environmental benefits.
• B) Chlorine is used for water purification because it reacts with bacteria to form reactive oxygen species.
• C) PVC is a highly biodegradable polymer used for various industrial applications.
• D) Bromine is primarily used for manufacturing PVC and chlorine-based disinfectants.

As you go down Group VII, the volatility of halogens decreases. This is because the size of the halogen molecules increases, leading to ................... van der Waals' forces between the molecules.

• stronger

• increases

• higher

3Cl2 (aq)+ 6NaOH(aq)→ 5NaCl(aq)+ NaClO3(aq)+3H2O(l) Chlorine undergoes a change in oxidation state from 0 to -1 (reduction) and from 0 to ............ (oxidation).

• +5

• 5