CSEC Chemistry Paper 1 May/June 2009 - Free CXC Past Paper with Answers

Items 1-2 refer to the following atoms represented by their electronic configuration.

(A) 2,4 (B) 2,8 (C) 2,8,6 (D) 2,8,8,2

Match each item below with one of the options above. Each option may be used more than once, once or not at all.

Which element

combines with chlorine to form ionic bonds?

forms many giant structures occuring both naturally and artificially?

In which of the following are radioactive isotopes NOT used?

'One mole of atoms of an element' refers to the mass of

1 atom of the element

the element which contains $6.0 \times 10^{23}$ atoms

the element which occupies $24.0 \, \text{dm}^3$ at s.t.p.

the element which combines completely with 12 g of carbon-12

Which of the following requires the LARGEST number of moles of electrons to liberate one mole of it?

Which of these elements has seven electrons in its outer shell?

The ionic equation for the reaction between an acid and a carbonate may be represented as

$H^{+}(aq) + CO_3^{2-}(aq) \rightarrow HCO_3^{-}(aq)$

$2H^{+}(aq) + CO_3^{2-}(aq) \rightarrow H_2CO_3(aq)$

$2H^{+}(aq) + CO_3^{2-}(aq) \rightarrow CO_2(g) + H_2O(l)$

$H^{+}(aq) + CO_3^{2-}(aq) \rightarrow CO_2(g) + H_2O(l)$

Which of the following can be referred to as a standard solution?

Iodine in 50 cm³ ethanol

Sodium chloride in 50 cm³ water

30 g of sodium chloride in water

30 g of iodine in 50 cm³ ethanol

Item 9 refers to the following illustrations of the electronic structure of four atoms.

P Q R S

Which pair of atoms forms covalent bonds when reacted together?

Which of the following is the type of crystal structure of iodine at room temperature and pressure?

A metallic bond is formed when

cations are held together by a sea of mobile electrons

positive metal ions are held together by a sea of anions

anions are held together by negative electrons

metal atoms are held together by molecular forces

Item 12 refers to the following graph which shows the boiling points of some straight-chain alcohols:

The MOST suitable method for separating the 4-carbon alcohol from a mixture with the 5-carbon alcohol is

fractional distillation

Which of the following is the correct formula for ammonium carbonate?

(NH₄)₂(CO₃)₂

Which of the following separation techniques is NOT used during the extraction of sucrose from sugar cane?

Which of the following does NOT affect the solubility of a substance?

A piece of calcium is added to some distilled water in a container and a gas is produced. The gas produced is expected to

relight a glowing splint

give a 'pop' with a lighted splint

decolourise acidified aqueous potassium manganate (VII)

turn acidified aqueous potassium dichromate green

Which set of elements has atoms with two electrons in their outer shells?

The transition elements

The oxide of a metal

Supplies protons as the only positive ions in aqueous solutions

When X and Y are stirred together in a beaker and the mixture filtered, X and Y are both present in the filtrate. Which of the following could describe the mixture formed by X and Y?

I. Solution II. Colloid III. Suspension

Which of the following compounds are acid salts?

I. NaH₂PO₄ II. CaSO₄ III. Al₂CO₃ IV. KHSO₄

reacts with an acid, liberating a gas which turns lime water milky?

reacts with sulphuric acid to produce hydrogen gas?

Acidified potassium manganate (VII) is

both an oxidising and reducing agent

The temperature at which neutralisation occurred is

Which of the following occurs when a metal atom becomes an ion?

It gains electrons and is oxidised

It gains electrons and is reduced.

It loses electrons and is oxidised

It loses electrons and is reduced.

Item 27 refers to the following information. 2.32 g of an oxide of iron, Fe, O,, are heated in dry hydrogen. When the reaction is complete, 1.68 g of iron are left. [Rel. atomic mass: Fe = 56; 0=16]

When this reaction is completed, the oxide of iron is completely

decomposed into its elements

In an experiment, on heating 402 g of mercury, a black powder with a mass of 434 g is obtained (Rel. atomic mass: Hg = 201; O=16). The balanced equation representing this reaction is

Hg(l) + O2(g) = HgO(s)

2Hg(l) + O2(g) = 2HgO(s)

Hg(s) + O2(g)=HgO(s)

2Hg(s) + O2(g)=2HgO(s)

Items 29-30 refer to the following options which represent the order of some metals in the activity series. (A) Magnesium (B) Iron (C) Lead (D) Copper In answering items 29-30, each option may be used once, more than once or not at all. Which element

would be liberated at the cathode from the aqueous solution of its salts during electrolysis?

forms an oxide which CANNOT be reduced by hydrogen?

Item 31 refers to the following apparatus which is used to measure the relative conductivity of various substances.

Which of the following solutions will NOT cause the bulb to light?

Aqueous ethanoic acid

Aqueous propanoic acid

Which of the following describes the effect on the AVERAGE rate of reaction AND the final volume of hydrogen gas collected in going from Experiment I to Experiment II?

Effect on Rate Effect on Final Volume of H₂(g) collected

Increased / Unchanged

Increased / Increased

Decreased / Decreased

Decreased / Unchanged

Which of the following apparatus is the MOST suitable for the electrolysis of copper (II) sulphate between copper electrodes?

The reaction occurring at the cathode during the electrolysis of copper sulphate using inert electrodes is given by the equation

Cu → Cu²⁺ + 2e⁻

Cu²⁺ + 2e⁻ → Cu

2H⁺ + 2e⁻ → H₂

4OH⁻ - 4e⁻ → 2H₂O + O₂

Which of the following is true when an aluminium pot is being anodised?

Aluminium is the anode in the cell.

Hydrogen is given off at the anode.

The electrolyte is a solution of sodium chloride.

A layer of aluminium hydroxide forms on the pot.

Items 36–37 refer to the following sequence of reactions involving iron compounds, where I, II, III and IV represent the stages involved. <br> <img src="image_crop_1.png"> <br>

In which stage is the oxidation state of iron increased?

A suitable reagent that could be used at IV is

aqueous sodium hydroxide

A recently discovered element is thought to be a metal. Which of the following physical properties would BEST confirm this?

Electrical conductivity

Chlorine can be obtained by

warming sodium chloride with concentrated sulphuric acid

boiling sodium chloride with manganese (IV) oxide

electrolysing a concentrated solution of sodium chloride

adding aqueous bromine to aqueous sodium chloride

Which of the following metals will react MOST vigorously with dilute acid?

The order of reactivity of these metals, with the MOST reactive first, is

Item 42 refers to the following types of chemical reactions which occur in the carbon cycle. I. Decomposition II. Combustion III. Photosynthesis

Which of these reactions would be responsible for returning carbon dioxide to the atmosphere?

Overtime, aluminium articles do not deteriorate ir air as do iron articles. Which of the following statements gives the correct reason for this?

Aluminium is higher up in the activity serie: than iron, therefore it is more resistant to corrosion than iron.

Both metals form oxide coats but aluminium oxide prevents further reaction, while the iron oxide does not.

Both metals form hydroxide coats but the aluminium hydroxide prevents further reaction, while the iron hydroxide doe not.

Aluminium is lower than iron in the activity series, therefore it reacts less readily with air than iron.

Which of the following substances forms dens white fumes with ammonia gas?

Which is the correct structural formula for X?

The compound, ethene, is described as being unsaturated. This means that the

carbon atoms in ethene are linked by single bonds

molecule has insufficient hydrogen atoms

carbon atoms in the molecule are very reactive

molecule contains at least one double bond

All members of a homologous series have similar

Item 48 refers to the following structures.

Which structures represent branched alkanes?

Item 49 refers to two organic compounds, I and II, of molecular formula C₃H₈O, with the following structures H H H H-C-C-C-H | | | H H H I H H H H-C-C-C-OH | | | H H H II

Compounds I and II are known as the

isomers of C₃H₈O

isotopes of C₃H₈O

condensed formulae of C₃H₈O

molecular formulae of C₃H₈O

Items 50-51 refer to the following compounds. I. Fats II. Nylon III. Proteins IV. Terylene

Which of the above compounds are synthetic?

Ester linkage exists in

Which of the following is used in the breathalyser test to detect the presence of alcohol?

Potassium dichromate

Which equation BEST represents the balanced equation for the reaction between aqueous ethanoic acid and magnesium?

CH₃COOH(aq) + Mg(s) → CH₃COOMg(aq) + H₂(g)

2CH₃COOH(aq) + Mg(s) → (CH₃COO)₂Mg(aq) + H₂(g)

2CH₃COOH(aq) + Mg(s) → 2CH₃COOMg(s) + H₂(g)

2CH₃COOH(aq) + 2Mg(s) → (2CH₃COO)₂Mg₂(aq) + H₂(g)

During the manufacture of ethanol by fermentation, the gas evolved

relights a glowing splint

burns with a blue flame

turns lime water milky

turns potassium dichromate green

The reaction of fats with concentrated aqueous sodium hydroxide is commonly referred to as

When ethene reacts with steam the ethene is

decomposed to carbon

converted to ethanol

converted to an ester

oxidised to carbon dioxide

Chlorofluorocarbons are MAINLY responsible for

the greenhouse effect

destruction of the ozone layer

destruction of limestone statues

Which two groups are present in the molecules of amino acids?

-NH, group and -COOH group

-NH, group and -OH group

-OH group and -COOH group

-COOH group and C=C group

Which of the following names refers to the product formed in the reaction

Nylon is a macromolecule which is held together by the same linkage as a protein molecule. What is the name given to this type of linkage?

CSEC Chemistry Paper 1 May/June 2009 - Free CXC Past Paper with Answers

CSEC Chemistry Paper 1 May/June 2009 Questions