AS & A Level Chemistry - 9701 Paper 1 2015 Winter Zone 2

Which type of bonding is never found in elements?

Arsenic chloride, AsCl_3, reacts with sodium borohydride, NaBH_4.
$$ p ext{AsCl}_3 + q ext{NaBH}_4 \rightarrow r ext{AsH}_3 + s ext{NaCl} + t ext{BCl}_3 $$
What are the numbers p, q, r, s and t when this equation is balanced correctly?
[Table_1]

Three substances have the physical properties shown in the table.

[Table_1]

What could be the identities of $U$, $V$ and $W$?

[Table_2]

Flask X contains 5 \text{dm}^3 of helium at 12 \text{kPa} pressure and flask Y contains 10 \text{dm}^3 of neon at 6 \text{kPa} pressure.
If the flasks are connected at constant temperature, what is the final pressure?

Calcium forms an ionic compound with carbon, called calcium carbide. The oxidation number of carbon in calcium carbide is −1.
Calcium carbide is readily hydrolysed by water giving two products only.
What could be the formulae of calcium carbide and the two products of hydrolysis?
[Table_1]

Hess' law may be used to determine enthalpy changes using average bond energies, as shown in the diagram.
[Image_1: Enthalpy Diagram showing U, V, and W between reactants and products]
U is the sum of the average bond energies of the reactants, and V is the sum of the average bond energies of the products.
For the reaction shown below, which expression will give a value for W, the enthalpy change of combustion of methane?
$$\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$$

The process of electrolysis can be used to purify copper, and to extract aluminium from an aluminium oxide/cryolite mixture.
What are the reactions at the anode in each of these processes? [Table_1]

Hydrogen can be obtained by reacting methane with steam.
$\text{CH}_4(g) + \text{H}_2\text{O}(g) \rightleftharpoons \text{CO}(g) + 3\text{H}_2(g) \quad \Delta H^\circ = +210 \, \text{kJ} \, \text{mol}^{-1}$
Which conditions of pressure and temperature will give the greatest equilibrium yield of hydrogen?
[Table with pressure and temperature options]

Nitrogen monoxide reacts with oxygen in a reversible reaction according to the equation shown below.

$$2\text{NO}(g) + \text{O}_2(g) \rightleftharpoons 2\text{NO}_2(g)$$

The partial pressures of each of the components in an equilibrium mixture are shown in the table.

[Table_1]

What is the numerical value of the equilibrium constant, $K_p$, for this equilibrium?

The decomposition reaction $SF_6(g) \rightarrow SF_4(g) + F_2(g)$ can be described by the reaction pathway diagram shown.

What are the values of $\Delta H^\circ$ and $E_a$ for this reaction?

Which row correctly describes what happens when the temperature of a chemical reaction is \textit{decreased}?
[Table_1: Activation energy and number of successful collisions table]

Which property decreases on descending Group II?

Use of the Data Booklet is relevant to this question.
The reaction between aluminium powder and anhydrous barium nitrate is used as the propellant in some fireworks. The metal oxides and nitrogen are the only products.
Which volume of nitrogen, measured under room conditions, is produced when 0.783 g of anhydrous barium nitrate reacts with an excess of aluminium?

Which chloride of a Period 3 element dissolves in water to form a solution with a pH of 7?

Which row correctly compares the electrical conductivity and first ionisation energy of magnesium and aluminium? [Table_1]

Use of the Data Booklet is relevant to this question.
Brine is concentrated aqueous sodium chloride.
In the commercial electrolysis of brine, the products are chlorine, hydrogen and sodium hydroxide.
What is the maximum yield of each of these products when 58.5kg of sodium chloride are electrolysed as brine?
[Table_1]

A student observed the reactions when sodium chloride and sodium iodide were each reacted separately with concentrated sulfuric acid and with concentrated phosphoric acid. Some observations are recorded in the table.

[Table_1]

Which deduction can be made from these observations?

A white powder is a mixture of sodium chloride and sodium iodide. It is dissolved in water in a test-tube. Excess aqueous silver nitrate is added to the test-tube. A precipitate, X, is observed.
Excess concentrated ammonia is then added to the test-tube containing X. After the test-tube has been shaken, a precipitate, Y, is observed.
Which statement about X or Y is correct?

Use of the Data Booklet is relevant to this question.
4.70g of an ammonium salt is heated with excess aqueous sodium hydroxide. The volume of ammonia gas given off, measured at room temperature and pressure, is 1.41 dm^3.
Which ammonium salt was used?

Which ester is formed when the alcohol $\text{CH}_3\text{CH}_2\text{OH}$ is reacted with $\text{CH}_3\text{CH}_2\text{CH}_2\text{CO}_2\text{H}$?

Which compound shows optical isomerism?

Methanoic acid, HCO$_2$H, has acidic properties similar to those of other carboxylic acids. In addition it can be oxidised by the same oxidising agents that are capable of oxidising aldehydes.
Which pair consists of two compounds that will give the same observations with Fehling's reagent?

Compound Q can be made from propanone.
[Image of compound Q]
Which types of reaction will Q undergo?

The depletion of the ozone layer in the upper atmosphere reduces the Earth's natural protection from harmful ultraviolet radiation.
Which compound would cause the most depletion of the ozone layer?

Compound X has been investigated for use as an artificial sweetener.

The two C–Cl bonds can be hydrolysed by hot NaOH(aq). The C-O-C bonds cannot be hydrolysed by hot NaOH(aq).
What are the numbers of specified types of –OH groups before and after hydrolysing the two C–Cl bonds?
[Table_1]

The compounds below are all produced by plants.
Each compound is warmed with acidified potassium dichromate(VI).
Which compound will give a different observation to the other three?

What is the mechanism for the reaction of ethanal, CH₃CHO, with hydrogen cyanide, HCN, in the presence of a base?

Menthol and menthone are both found in peppermint oil.

Which statement about these compounds is correct?

What is the skeletal formula of 2-methylpentan-1-ol?

The structure of aspartame, which is used as an artificial sweetener, is shown.
If aspartame is warmed in aqueous alkali, which of bonds 1 and 2 will be broken?

The relative molecular mass, $M_r$, of a particular sample of chlorine is 72.0.
Which properties of the atoms in this sample will be the same for all of the atoms?
1. radius
2. nucleon number
3. isotopic mass

Which of the following influence the size of the ionisation energy of an atom?
1. the amount of shielding by the inner electrons
2. the charge on the nucleus
3. the distance between the outer electrons and the nucleus

Which equations can apply to an ideal gas?
[\( p = \text{pressure}, \ V = \text{volume}, \ M = \text{molar mass}, \ \rho = \text{density}, \ c = \text{concentration}, \ R = \text{gas constant}, \ T = \text{temperature} \)]

Ammonia and chlorine react in the gas phase.

$$\text{8NH}_3 + 3\text{Cl}_2 \rightarrow \text{N}_2 + 6\text{NH}_4\text{Cl}$$

Which statements are correct?
1. Each nitrogen atom is oxidised.
2. Each chlorine atom is reduced.
3. Ammonia behaves as a base.

Which statements about calcium and strontium compounds are correct?
1. When calcium oxide and strontium oxide are added to water they both produce alkalis.
2. Calcium hydroxide is more soluble than strontium hydroxide.
3. Calcium sulfate is less soluble than strontium sulfate.

Which descriptions of the ammonium ion are correct?
1. It contains ten electrons.
2. It has a bond angle of 109.5°.
3. It has only three bonding pairs of electrons.

Compound Q is obtained by adding H$_2$O across the double bond in compound P.

Which statements about these two compounds are correct?
1. P shows cis-trans isomerism.
2. Q contains two chiral centres.
3. Q is a tertiary alcohol.

X is an organic compound. X gives a precipitate with aqueous silver nitrate. Some or all of this precipitate remains undissolved when excess dilute aqueous ammonia is added.
What could be the identity of X?

Which compounds, on heating with excess concentrated sulfuric acid, produce only one product with molecular formula $C_7H_{10}$?

Compound Z is heated with concentrated acidified potassium manganate(VII). This produces an equimolar mixture of CO_2 and CH_3COCH_2CH_2CH(COCH_3)CH_2CO_2H.
What could be the structural formula of Z?