Chemistry 9701 · AS & A Level · Group 17

Group 17 — practice question

Iodine is used in a wide range of inorganic reactions and organic reactions.
(a(i))[2]

State and explain the pattern in volatility of the halogens, from chlorine to iodine.

(a(ii))[1]

Explain why HI is the least thermally stable among HCl, HBr and HI.

(a(iii))[2]

The table gives the electronegativity values for hydrogen, fluorine and iodine. Explain, in terms of intermolecular forces, why HI has a lower boiling point than HF.

(a(iv))[1]

Iodine reacts with hot concentrated aqueous sodium hydroxide in the same way as chlorine. Write an equation for the reaction of iodine and hot aqueous sodium hydroxide.

(b(i))[1]

$\text{CH}_3\text{I}$ can be prepared from methanol, $\text{CH}_3\text{OH}$. Identify a reagent that can convert $\text{CH}_3\text{OH}$ to $\text{CH}_3\text{I}$.

(b(ii))[1]

$1,2$-diiodoethane, $\text{CH}_2\text{ICH}_2\text{I}$, can be prepared by bubbling ethene into liquid iodine. Fully name the type of mechanism shown in this reaction.

(c(i))[1]

Name J.

(c(ii))[1]

J reacts with NaOH(aq) to form K. Fully name the mechanism for the reaction of J with NaOH(aq) to form K.

(c(iii))[1]

$J$ reacts with $\text{NaOH}$ dissolved in ethanol to form a mixture of two alkenes, $L$ and $M$. Alkene $L$ is shown. In the box provided, draw the structure of $M$.

(c(iv))[1]

Explain why $L$ does not show geometrical (cis-trans) isomerism.

(c(v))[1]

$L$ reacts with hot concentrated acidified $\text{KMnO}_4\text{(aq)}$ to form propanone and one other organic product. Identify the other organic product.

(c(vi))[2]

Propanone reacts with excess alkaline aqueous iodine. Complete and balance the equation for this reaction: $\text{CH}_3\text{COCH}_3 + \ldots \text{I}_2 + \ldots \text{OH}^- \rightarrow \ldots \text{CH}_3\text{COO}^- + \ldots \text{H}_2\text{O} + \ldots \text{I}^- + \ldots$.

(c(vii))[1]

State one observation that can be made in the reaction in (c)(vi).

Worked solution & mark scheme

This 16-mark question has a full step-by-step worked solution and mark scheme. One marking point: Volatility falls down the group

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI