[Maximum number: 1]

Hydrogen iodide, HI, is a colourless gas at room temperature.

(a)

In the laboratory, HI(aq) can be formed in a two-step process.

step $13 \mathrm{I}_{2}(\mathrm{~s})+2 \mathrm{P}(\mathrm{s}) \rightarrow 2 \mathrm{PI}_{3}(\mathrm{~s})$

step $2 \mathrm{PI}_{3}(\mathrm{~s})+3 \mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{H}_{3} \mathrm{PO}_{3}(\mathrm{aq})+3 \mathrm{HI}(\mathrm{aq})$

[ 1 ]

(i)

Name the type of reaction in step 2 .

[ 1 ]

[Maximum number: 13]

Elements and compounds which have small molecules usually exist as gases or liquids.

(a)

HCN reacts with ethanal, $\mathrm{CH}_{3} \mathrm{CHO}$ .

[ 5 ]

(i)

What type of reaction is this?

(a)

Halogenoalkanes can undergo homolytic fission in the upper atmosphere.

[ 3 ]

(i)

Explain the term homolytic fission.

(ii)

Suggest the most likely organic radical that would be formed by the homolytic fission of bromochloromethane, $\mathrm{CH}_{2} \mathrm{BrCl}$ . Explain your answer.

[ 3 ]

(a)

The major source of sulfur for the manufacture of sulfuric acid by the Contact process is the de-sulfurisation of 'sour' natural gas. Many natural gas wells produce a mixture of volatile hydrocarbons (mainly $\mathrm{CH}_{4}$ and $\mathrm{C}_{2} \mathrm{H}_{6}$ ) together with up to 25 % hydrogen sulfide, $\mathrm{H}_{2} \mathrm{~S}$ .

(i)

What type of reaction is occurring here?
The recovered $\mathrm{H}_{2} \mathrm{~S}$ is converted to sulfur by the following two reactions.
I Part of the $\mathrm{H}_{2} \mathrm{~S}$ is burned in air.

\mathrm{H}_{2} \mathrm{~S}+1.5 \mathrm{O}_{2} \rightarrow \mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O}

II The gas stream resulting from reaction I is then blended with the remaining $\mathrm{H}_{2} \mathrm{~S}$ and fed into an iron oxide catalyst bed, where sulfur and water are produced according to the following equation.

2 \mathrm{H}_{2} \mathrm{~S}(\mathrm{~g})+\mathrm{SO}_{2}(\mathrm{~g}) \rightarrow 3 \mathrm{~S}(\mathrm{~g})+2 \mathrm{H}_{2} \mathrm{O}(\mathrm{~g})

[Maximum number: 1]

Carbon and silicon are elements in Group 14.

(a)

0.144 g of $\mathrm{C}_{60}$ was placed in a $100 \mathrm{~cm}^{3}$ container of hydrogen gas at $20^{\circ} \mathrm{C}$ and $1.00 \times 10^{5} \mathrm{~Pa}$ .

The container was heated to make the $\mathrm{C}_{60}$ and hydrogen gas react.
The reaction occurred as shown in the equation.

\mathrm{C}_{60}(\mathrm{~s})+x \mathrm{H}_{2}(\mathrm{~g}) \rightarrow \mathrm{C}_{60} \mathrm{H}_{2 x}(\mathrm{~s})

After the reaction, the container was allowed to cool to $20^{\circ} \mathrm{C}$ . The pressure decreased to $2.21 \times 10^{4} \mathrm{~Pa}$ . All of the $\mathrm{C}_{60}$ had reacted.

[ 1 ]

(i)

Name the type of reaction that occurred.

[ 1 ]

[Maximum number: 1]

The molecular formula $\mathrm{C}_{3} \mathrm{H}_{6}$ represents the compounds propene and cyclopropane.

propene

cyclopropane

(a)

Under suitable conditions, propene and cyclopropane each react with chlorine.

[ 1 ]

(i)

With propene, 1,2-dichloropropane, $\mathrm{CH}_{3} \mathrm{CHClCH}_{2} \mathrm{Cl}$ is formed.

State fully what type of reaction this is.

[ 1 ]

(a)

(i)

Sodium cyanate, NaNCO, is used in the production of isocyanic acid.

Sodium cyanate is prepared commercially by reacting urea, $\left(\mathrm{NH}_{2}\right)_{2} \mathrm{CO}$ , with sodium carbonate. Other products in this reaction are carbon dioxide, ammonia and steam.

Write an equation for the production of NaNCO by this method.

[ 1 ]

[Maximum number: 2]

Chlorine, $\mathrm{Cl}_{2}$ , is a reactive yellow-green gas. It is a strong oxidising agent.

(a)

Dichloromethane, $\mathrm{CH}_{2} \mathrm{Cl}_{2}$ , is widely used as an organic solvent.
$\mathrm{CH}_{2} \mathrm{Cl}_{2}$ can be prepared by reacting $\mathrm{CH}_{3} \mathrm{Cl}$ and $\mathrm{Cl}_{2}$ at room temperature.
The reaction proceeds via several steps, as shown.

\begin{aligned} \mathrm{Cl}_{2} & \xrightarrow{\text { initiation }} 2 \mathrm{Cl} l^{\bullet} \\ \mathrm{Cl} \cdot+\mathrm{CH}_{3} \mathrm{Cl} & \xrightarrow{\text { propagation 1 }} \mathrm{HCl}+{ }^{\cdot} \mathrm{CH}_{2} \mathrm{Cl} \\ \mathrm{Cl}_{2}+\cdot{ }^{\cdot} \mathrm{CH}_{2} \mathrm{Cl} & \xrightarrow{\text { propagation 2 }} \text { products } \\ \mathrm{C} l^{\cdot}+\cdot{ }^{\cdot} \mathrm{CH}_{2} \mathrm{Cl} & \xrightarrow{\text { final step }} \mathrm{CH}_{2} \mathrm{Cl}_{2} \end{aligned}

[ 2 ]

(i)

Give the name of the mechanism of this reaction.

[ 1 ]

(ii)

Name the type of reaction shown in the final step.

[ 1 ]

[Maximum number: 2]

Menthol and menthone, the main constituents of oil of peppermint, can be made synthetically from thymol by the following route.

(a)

State the type of reaction of
- reaction I,
- reaction II.

[ 2 ]

[Maximum number: 1]

Sucrose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$ , reacts with water to form glucose and fructose in reaction A.

$reaction \(\mathbf{A$

reaction \(\mathbf{A

(a)

Suggest a name for this type of reaction.

[ 1 ]