CSEC Chemistry Paper 1 January 2008 - Free CXC Past Paper with Answers

Which of the following is a characteristic of a strong acid?

It is a poor conductor of electricity.

It has a pH greater than 7.

It completely dissociates in water.

It reacts with water to form hydroxide ions.

Which of the following oxides is amphoteric?

$\text{Al}_2\text{O}_3$

$\text{P}_4\text{O}_{10}$

The reaction below represents the preparation of a gas. $\text{NH}_4\text{Cl(s)} + \text{NaOH(aq)} \rightarrow \text{NaCl(aq)} + \text{H}_2\text{O(l)} + \text{X(g)}$ What is gas X?

Which of the following is a characteristic of a base?

It has a pH less than 7.

It turns red litmus paper blue.

It reacts with acids to form salt and water only.

It is a poor conductor of electricity in aqueous solution.

Which of the following salts is insoluble in water?

$\text{Na}_2\text{SO}_4$

Which of the following is a characteristic of a salt?

It is formed from the reaction of an acid with a base.

It is always soluble in water.

It is always a solid at room temperature.

It is always neutral.

Which of the following is a characteristic of a neutral substance?

It turns red litmus paper blue.

It reacts with acids to form salt and water.

Which of the following is a characteristic of an indicator?

It changes colour in acidic solutions only.

It changes colour in basic solutions only.

It changes colour in neutral solutions only.

It changes colour over a specific pH range.

Which of the following statements about 1 mole of a gas would be correct? I. It contains $6 \times 10^{23}$ individual species. II. It is the relative atomic mass in grams. III. It occupies 22.4 dm³ at standard temperature and pressure. IV. It occupies the same volume as any other gas at r.t.p.

From the information given in the table below, which of the substances A, B, C or D, is MOST likely sodium chloride?

The SMALLEST particle of a chemical compound that can take part in a reaction is the

The number of shared electron pairs in a methane molecule is

How many covalent bonds are there in a nitrogen molecule?

A separating funnel can be used to separate a mixture of

water and sodium chloride

kerosene and sodium chloride

A substance X, with a boiling point of 60°C, is miscible with another liquid Y, of boiling point 80°C. A mixture of these two liquids can BEST be separated into its components by

use of a separating funnel

fractional distillation

Which of the following atoms would NOT form a positive ion?

When two substances, 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

the rate of reaction and

solubility of product

reaction with litmus

Which of the following is NOT true of the group of elements known as the halogens?

The boiling point of the elements increases as their atomic numbers increase.

The oxidizing power of the elements decreases as their atomic numbers increase.

They are all nonmetals.

They form negative ions by the loss of electrons from their atoms.

A solution has a pH of 1. This solution would be expected to

react with zinc metal to produce hydrogen

react with zinc metal to produce a solution of pH 10

neutralize a solution of pH 4

react with hydrochloric acid to produce a salt and water

Which of the following substances is the oxide of a metal?

Item 12 refers to 1 mole of EACH of the following acids. I. H₂SO₄ II. CH₃COOH III. H₂CO₃ IV. HNO₃

Which TWO of the above acids require more than one mole of NaOH(aq) for complete neutralization?

Which of the following is an acid salt?

Which of the following ionic equations involves oxidation?

S²⁻ – 2e⁻ → S

Cl₂ + 2e⁻ → 2Cl⁻

2H⁺ + 2e⁻ → H₂

What is the oxidation number of carbon in EACH of the following compounds?: CH₄ CO CO₂

In which of the following reactions is sulphur dioxide acting as an oxidising agent?

2SO₂(g) + O₂(g) → 2SO₃(g)

SO₂(g) + 2H₂O(l) → 2H₂O(l) + 3S(s)

SO₂(g) + H₂O(l) → H₂SO₄(aq)

SO₂(g) + 2HNO₃(aq) → H₂SO₄(aq) + 2NO₂(g)

A substance that conducts an electric current but remains chemically unchanged is

aqueous copper (II) sulphate

Which of the following statements about ionic compounds is true?

They contain molecules.

They are solids and vaporize easily.

They usually dissolve in organic solvents.

They conduct electricity when melted or dissolved in water.

Which of the following statements about electrolysis is NOT correct?

The electrons leave the solution by the positive electrode.

Decomposition of the electrolyte at the electrode is due to an electric current.

The electrons enter the solution by the negative electrode.

Decomposition of the electrolyte at the electrode produces an electric current.

Item 30 refers to the following graph which shows the changes in temperature with time, for a substance heated until no further physical changes take place.

During which portion of the curve is the substance a liquid only?

When heat is given off to the surroundings during a chemical reaction, it is because bond breaking

as well as bond formation releases energy

requires less energy than is released when new bonds are formed

requires more energy than that released when new bonds are formed

is an endothermic process whereas bond making is an exothermic one

Ions which are NOT changed in a reaction are called

A piece of metal is reacted with an acid to produce hydrogen gas. Which of the following procedures should be employed in order to increase the rate of the reaction?

I. Increasing the temperature at which the reaction is carried out II. Subdividing the lump of metal III. Reducing the concentration of the acid

During the electrolysis of aqueous copper (II) sulphate solution using inert electrodes, the ions migrating to the cathode are

$\text{Cu}^{2+}(\text{aq})$ and $\text{SO}_4^{2-}(\text{aq})$

$\text{H}^+(\text{aq})$ and $\text{OH}^-(\text{aq})$

$\text{Cu}^{2+}(\text{aq})$ and $\text{H}^+(\text{aq})$

$\text{SO}_4^{2-}(\text{aq})$ and $\text{OH}^-(\text{aq})$

When a concentrated solution of sodium chloride is electrolysed using carbon electrodes

sodium is liberated at the cathode

the solution at the cathode is alkaline

oxygen is liberated at the anode

chlorine is liberated at the anode

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

carbon atoms in ethene are linked by single bonds.

molecule contains at least one double bond

carbon atoms in the molecule are very reactive

molecule has insufficient hydrogen atoms

The correct structural formula for X is

Which of the following compounds is NOT a member of the alkene series?

Octane, the major component of gasoline, is an alkane with 8 carbon atoms per molecule. Which of the following is the formula of octane?

Item 40 refers to two compounds of formulae CH₃–CH=CH–CH₃ and CH₂=CH–CH₂–CH₃, respectively. Which of the following are the same for these compounds? I. Molecular formula II. Empirical formula III. Functional group

Item 41 refers to the following information. W represents the structure of one molecule of the starting material used in an organic reaction. Z represents the structure of part of the product formed.

The reaction can be classified as

addition polymerization

condensation polymerization

Complete oxidation with acidified potassium dichromate (VI) solution...

CH₃CH₂OH → CH₃COOH

CH₃CH₂OH → CH₃CHO

CH₃CH₂OH → C₂H₄

CH₃CH₂OH → 2CO₂ + 3H₂O

The production of an alkene when heated with concentrated sulphuric acid

CH₃CH₂OH → CH₃COOH

CH₃CH₂OH → CH₃CHO

CH₃CH₂OH → C₂H₄

CH₃CH₂OH → 2CO₂ + 3H₂O

When ethanoic acid and ethanol react to form ethyl ethanoate, the catalyst used is

dilute hydrochloric acid

concentrated hydrochloric acid

dilute sulphuric acid

concentrated sulphuric acid

The residue in the fractional distillation of petroleum is

The fermentation of sugars, using glucose as the substrate, can be represented by the equation

$C_6H_{12}O_6 \rightarrow 6CO_2 + 6H_2O$

$C_6H_{12}O_6 + C_6H_{12}O_6 \rightarrow C_{12}H_{22}O_{11} + H_2O$

$C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2$

$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$

Hydrocarbons occur naturally in

Items 48 - 42 refer to the following compounds. (A) Fats (B) Starch (C) Proteins (D) Polyamides

In answering items 48-49, each compound may be used more than once, once or not at all.

Which compound produces amino acids when hydrolysed?

Which compound is NOT considered to be a polymer?

Which of the following types of polymers may be derived from compounds containing the partial structure shown below? H | -C-COOH | NH₂

Which of the following compounds are naturally occurring? I. Terylene II. Nylon III. Fats IV. Proteins

The extraction of sucrose from sugarcane is through

addition polymerization

condensation polymerization

Which of the following may be true of metals? I. They form solid chlorides. II. They generally form basic oxides. III. They conduct electricity only when molten.

Which of the following elements reacts with water?

Item 55 refers to the Haber process for the production of ammonia, according to the equation N₂(g) + 3H₂(g) ⇌ 2NH₃(g) ΔH = -92 kJ mol⁻¹

The catalyst used in this process is

Which of the following gives the correct order of decreasing reactivity, (MOST reactive first), for metals P, Q and R?

Which of the following statements explains why, overtime, aluminium articles DO NOT deteriorate in air as do iron articles?

Aluminium is higher up in the activity series 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 does not.

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

Which of the following aqueous solutions will produce a blue precipitate with aqueous sodium hydroxide?

Which of the following compounds may be used to counteract the effects of acid rain on the soil?

A certain metal nitrate produces two gases when heated and a brown solid when it reacts with zinc. Which of the following could be the metal nitrate?

CSEC Chemistry Paper 1 January 2008 - Free CXC Past Paper with Answers

CSEC Chemistry Paper 1 January 2008 Questions