AS & A Level Chemistry - 9701 Paper 1 2009 Winter Zone 2

0.200 mol of a hydrocarbon undergo complete combustion to give 35.2 g of carbon dioxide and 14.4 g of water as the only products.
What is the molecular formula of the hydrocarbon?

Use of the Data Booklet is relevant to this question.
The graph represents the variation of a property of the Group II elements.

What is this property?

The antidote molecule shown can help to prevent liver damage if someone takes too many paracetamol tablets. What is the order of decreasing size of the bond angles x, y, and z?

Which molecule has the largest overall dipole?

The first stage in the industrial production of nitric acid from ammonia can be represented by the following equation.
4NH$_3$(g) + 5O$_2$(g) ⇌ 4NO(g) + 6H$_2$O(g)
Using the following standard enthalpy change of formation data, what is the value of the standard enthalpy change, ΔH$^{°}$, for this reaction?
[Table_1]

Which conversion involves a reduction of chromium?

The equilibrium \[ \text{N}_2(g) + \text{O}_2(g) ightleftharpoons 2\text{NO}(g) \quad \Delta H = +180 \, \text{kJ mol}^{-1} \] contributes to a series of reactions producing photochemical smog.
Which factors would affect the value of \( K_p \) of the above equilibrium?
[Table_1:
change in pressure, change in temperature, presence or absence of a catalyst
A ✔ ✔ ✖
B ✔ ✖ ✔
C ✖ ✔ ✔
D ✖ ✖ ✖ ]

PCl\textsubscript{5} dissociates as follows:
\( \text{PCl}_5(g) \rightarrow \text{PCl}_3(g) + \text{Cl}_2(g) \)
The extent of dissociation is 13\% at 160 °C and 100\% at 300 °C.
Which pair of statements about this formation of PCl\textsubscript{3} is correct?

Four reactions of the type shown are studied at the same temperature.
$X(g) + Y(g) \rightarrow Z(g)$
Which is the correct reaction pathway diagram for the reaction that would proceed most rapidly and with the highest yield?

Photochromic glass, used for sunglasses, darkens when exposed to bright light and becomes more transparent again when the light is less bright. The depth of colour of the glass is related to the concentration of silver atoms.

The following reactions are involved.
reaction 1 $\text{Ag}^+ + \text{Cl}^- \rightleftharpoons \text{Ag} + \text{Cl}$
reaction 2 $\text{Cu}^+ + \text{Cl}^- \rightarrow \text{Cu}^{2+} + \text{Cl}^-$
reaction 3 $\text{Cu}^{2+} + \text{Ag} \rightarrow \text{Cu}^+ + \text{Ag}^+$

Which statement about these reactions is correct?

The following graph shows the variation of a property of the first 20 elements in the Periodic Table with the atomic number of the element. What is the property?

Which statement correctly describes what happens when silicon tetrachloride is added to water?

The oxide and chloride of an element $X$ are separately mixed with water. The two resulting solutions have the same effect on litmus. What is element $X$?

Which graph correctly describes a trend found in the halogen group?
[X represents a halogen atom.]

During electrolysis of brine in a diaphragm cell, chlorine, hydrogen and sodium hydroxide are produced.
What is the molar ratio of these products?

When sulfur trioxide is manufactured from sulfur dioxide and oxygen, using the Contact process, which condition affects the value of the equilibrium constant, $K_c$?

Most modern cars are fitted with three-way catalytic converters in the exhaust system. Which three gases are removed by such a catalytic converter?

In an historically famous experiment Wöhler heated 'inorganic' ammonium cyanate in the absence of air. The only product of the reaction was 'organic' urea, CO(NH_2)_2. No other products were formed in the reaction.
What is the formula of the cyanate ion present in ammonium cyanate?

The drug cortisone has the formula shown.
In addition to those chiral centres marked by an asterisk (*), how many other chiral centres are present in the cortisone molecule?

The presence of 11-cis retinal, $C_{20}H_{28}O$, in cells in the eye is important for vision.
The structure of retinal includes an aldehyde group, a cyclohexene ring and a long aliphatic side chain, in which a carbon-carbon double bond exists between carbons numbered 11 and 12.
Which pair of statements about 11-cis retinal could be correct?
[Table of statements about >C=C< double bonds and their arrangement]

What is the least number of carbon atoms in a non-cyclic alkane molecule that has a chiral centre?

The following diagram represents the structure of a possible polymer.

By which method might this polymer be made?

Sorbic acid is used as a food preservative because it kills fungi and moulds.

[Image_1: Sorbic acid structural formula]

Sorbic acid will react with

• hydrogen in the presence of a nickel catalyst,
• bromine in an organic solvent.

Bromine reacts with ethene to form 1,2-dibromoethane.
What is the correct description of the organic intermediate in this reaction?

Which equation represents a valid propagation step in the free radical reaction between ethane and chlorine?

The naturally-occurring molecule civetone is found in a gland of the African civet cat and has been used in perfumery.

With which reagent will civetone not react?

Cyanohydrins can be made from carbonyl compounds by generating $\text{CN}^-\text{ ions}$ from HCN in the presence of a weak base.

In a similar reaction, $\text{-CH}_2\text{CO}_2\text{CH}_3$ ions are generated from $\text{CH}_3\text{CO}_2\text{CH}_3$ by strong bases.
Which compound can be made from an aldehyde and $\text{CH}_3\text{CO}_2\text{CH}_3$ in the presence of a strong base?

The characteristic odour of rum is attributed to the compound 2-ethyl-3-methylbutanoic acid.\[ \begin{align*} &\text{H}_3\text{C} &&&&&\text{CH}_3 \ &&&|| && \text{C}_2\text{H}_5\ &&\text{C} &&\text{C} &&\begin{align*} \text{OH} \ H_3\text{C} \end{align*} \ &&\text{H} &&\hspace{1cm}\text{O} \end{align*} \] 2-ethyl-3-methylbutanoic acid
Which compound will produce 2-ethyl-3-methylbutanoic acid by heating under reflux with alcoholic sodium cyanide and subsequent acid hydrolysis of the reaction product?

The acarid mite releases extit{lardolure} to attract other mites to a host. This chemical can be destroyed by hydrolysis with acid.
\[ \text{CH}_3\text{CH}_2\text{CH}_2[\text{CH(CH}_3)\text{CH}_2]_3\text{CH(CH}_3)\text{O—C—H} \]
A simplified formula for extit{lardolure} may be written as follows.
\[ \text{RCH(CH}_3)\text{O—C—H} \]
What are the products of its hydrolysis?

An element X consists of four isotopes. The mass spectrum of X is shown in the diagram. What is the relative atomic mass of X?

Which physical properties are due to hydrogen bonding between water molecules?
1. Water has a higher boiling point than H$_2$S.
2. Ice floats on water.
3. The H–O–H bond angle in water is approximately 104\degree.

Which equilibria, in which all species are gaseous, would have equilibrium constants, $K_p$, with no units?
1. sulfur dioxide and oxygen in equilibrium with sulfur trioxide
2. hydrogen and iodine in equilibrium with hydrogen iodide
3. carbon monoxide and steam in equilibrium with carbon dioxide and hydrogen

Why does a mixture of hydrogen gas and bromine gas react together faster at a temperature of 500K than it does at a temperature of 400K?
1. A higher proportion of effective collisions occurs at 500K.
2. Hydrogen molecules and bromine molecules collide more frequently at 500K.
3. The activation energy of the reaction is lower at 500K.

A farmer added lime to damp soil, followed by the nitrogenous fertiliser ammonium sulfate. A chemical reaction occurred in the soil. Which substances were formed in this reaction?

Which statements about the reaction of solid sodium bromide with concentrated sulfuric acid are correct?
1. Hydrogen bromide is a product of the reaction.
2. Sulfuric acid is oxidised to sulfur dioxide.
3. Bromide ions are reduced to bromine.

Which statements are true for an $S_N2$ reaction?
1. One bond is broken as another bond is formed.
2. The formation of a transition state involves the collision of two molecules or ions.
3. A carbon atom in the transition state is bonded, either fully or partially, to five other atoms.

The chlorine free radical takes part in the destruction of the ozone layer. Which statements about this free radical are correct?
1. It is formed by the heterolytic fission of the covalent bond in a chlorine-containing molecule.
2. It has a single unpaired electron.
3. It has the same electron arrangement as a chlorine atom.

The diagram shows an experiment.

Which processes could be demonstrated by using the above apparatus?
1. the oxidation of ethanol (the liquid X)
2. the dehydration of ethanol (the liquid X)
3. the cracking of paraffin (the liquid X)

A compound has a relative molecular mass of 88 and its molecule contains only four carbon atoms. What could this compound be?

A monomer undergoes addition polymerisation. A 1 mol sample of the monomer is completely polymerised.
How many moles of polymer might, theoretically, be formed?