CSEC Chemistry Paper 1 May/June 2006 - Free CXC Past Paper with Answers

Sulphur and oxygen are in the same group of the periodic table because

they can react with each other

the atomic number of sulphur is 16 and the relative atomic mass of oxygen 16

they have the same number of electrons in their outer shell

they can form covalent compounds

If atom X forms an ion, the charge on the ion would MOST likely be

Which of the following oxides does NOT react with acids to form only a salt and water?

Which two of the following statements about covalent compounds are true?

I. They are mainly solids. II. They usually have low melting and boiling points. III. They are usually insoluble in water. IV. They contain only ions.

Which of the following statements illustrates osmosis?

Pollen dust in random motion in water

Movement of perfume molecules through the air in a room

Movement of water molecules across a cellophane membrane into a concentrated glucose solution

Movement of food colouring molecules in a dilute aqueous solution

Radioactive isotopes are NOT normally used in the

determination of the age of fossils

treatment of influenza

powering of certain types of submarines

PO₄³⁻ is the formula for the phosphate anion. What is the formula of calcium phosphate? (Calcium is element number 20.)

From which of the following can a solid be obtained by the process of sedimentation?

In the reaction between zinc and dilute sulphuric acid

an insoluble salt is formed

neutralisation occurs

oxidation and reduction occur

Which of the following elements exhibits allotrophy?

Which of the following may be defined as that quantity of a substance which contains 6.02 x 10^23 particles of that substance?

The values of x and y respectively in the equation x KOH + 3 Br₂ → y KBr + KBrO₃ + 3 H₂O are

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 solid sodium chloride

A substance X, with a boiling point of 58 °C, is miscible with another liquid Y, of boiling point 94 °C. A mixture of these two liquids can BEST be separated into its components by

fractional distillation

use of a separating funnel

Which of the following gases is composed of molecules containing two atoms each?

A compound when treated with concentrated hydrochloric acid gives off a green gas which bleaches moist red litmus paper.

The gas given off is

In which of the following substances will electrolysis NOT occur when an electrical current is passed through it?

Sodium hydroxide solution

Molten sodium chloride

Solid sodium chloride

Dilute sulphuric acid

Sulphuric acid is a stronger acid than ethanoic acid (acetic acid) ión aqueous solution because sulphuric acid

is obtainable in high concentrations

ionises to a greater extent than ethanoic acid

is more corrosive than ethanoic acid

causes sugar-to-char whereas ethanoic acid does not

Barium is below calcium in Group II of the periodic table. When these metals react with water, the main differences in observation would be the rate of reaction and

solubility of product

reaction with litmus

number of products formed

In which formula does hydrogen have a negative oxidation number?

Item 22 refers to the following diagram.

The bulb will light the MOST brightly when X is

aqueous ethanoic acid

dilute sulphuric acid

Two solutions are mixed in order to demonstrate endothermic change. Which of the following techniques will be MOST appropriate?

Taking mass readings

Taking temperature readings

Carefully observing colour changes

Monitoring the pH of the solutions

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

$\frac{24}{11}$ Na and $\frac{23}{11}$ Na are isotopes because they

react vigorously with water

have the same relative atomic mass

have the same number of protons

When solid lead nitrate is heated, it decomposes giving off nitrogen (IV) oxide and oxygen. The balanced equation for this reaction is

$2Pb(NO_3)_2(s) \rightarrow 2PbO(s) + 4NO_2(g) + O_2(g)$

$Pb(NO_3)_2(s) \rightarrow PbO(s) + NO_2(g) + O_2(g)$

$Pb(NO_3)_2(s) \rightarrow PbO(s) + 2NO_2(g) + \frac{1}{2}O_2(g)$

$2Pb(NO_3)_2(s) \rightarrow PbO(s) + 2NO_2(g) + O_2(g)$

Which of the following halogens is a liquid at room temperature?

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

neutralise a solution of pH 4

react with hydrochloric acid to produce a salt and water

'Ionic bond formation' is BEST described as the result of the

sharing of electrons between the atoms of a metal and non-metal to achieve stability

donation of electrons from a metal to a non-metal to achieve stability

donation of electrons from a non-metal to a metal to achieve stability

attraction between the positively charged ions of a metal and a pool of electrons

During which sections of the graph is the substance changing its state?

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

releases energy as well as bond making

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

An excess of magnesium powder is added to 50 cm³ of dilute sulphuric acid, and the reaction is allowed to continue until no more hydrogen evolves. Which of the following graphs BEST represents the complete reaction?

A lump of metal is reacted with an acid to produce hydrogen gas. Which of the following procedures could 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

When 100 cm³ of 2 mol dm⁻³ hydrochloric acid (an excess) are added to 5.0g of granulated zinc, hydrogen is evolved at a certain rate. If 5.0g of powdered zinc were used instead, the rate of production of hydrogen would -

increase because of the greater concentration of zinc

increase because of the increased surface area of zinc

decrease because of the decreased reactivity of zinc powder

decrease because of the lower solubility of powdered zinc

Which of the following aqueous solutions contains 1 mole of hydrogen ions?

1 dm³ of 1.0 mol dm⁻³ H₂SO₄

1 dm³ of 1 mol dm⁻³ CH₃COOH

2 dm³ of 0.5 mol dm⁻³ H₂SO₄

2 dm³ of 0.5 mol dm⁻³ HCl

Ethanol can react with concentrated sulphuric acid to produce ethene. This reaction is referred to as

Which of the following equations represents a condensation reaction?

nC₆H₁₂O₆ → (C₆H₁₀O₅)n + nH₂O

CH₃CH=CH₂ + HBr → CH₃ - CH₂ - CH₂Br

CH₃CH₂CH₂ + Br₂ → CH₃CH₂CH₂Br + HBr

CH₃CH₂COOH + NaOH → CH₃CH₂COONa + H₂O

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?

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

The number of isomers of butane $C_4H_{10}$ is

Decolourises bromine water

Is an unsaturated hydrocarbon

Ethanol may be used as a fuel because it

has a high heat of combustion

is easily converted to carbon

is easily converted to ethane

has a low heat of formation

Glucose is converted to starch or cellulose by

addition polymerisation

oxidation and reduction

condensation polymerisation

Which of the following represents the linkage?

Which of the following substances give a blue colouration with iodine?

Hydrocarbons are obtained naturally from

During the manufacture of ethanol by fermentation, the gas evolved

relights a glowing splint

burns with a blue flame

turns acidified potassium dichromate green

turns lime water cloudy

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

During the digestion of polysaccharide by the human body, the main process occurring is

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.

What is observed when EXCESS aqueous ammonia is added to a solution of copper (II) sulphate?

Light blue precipitate

Items 55 and 56 refer to the following equation. N₂(g)+3H2(g)=2NH,(g), AH = -92 kJ mol-¹

The role of the catalyst in this reaction is to

increase the yield of ammonia in the mixture

lower the energy level of the reac- tants

increase the rate of production of ammonia

decrease the amount of heat lost

The notation AH=-92kJmol-' means that

92 kJ of energy are required for the reaction to proceed

92 kJ of energy are released during the reaction

92 kJ of energy are required to break the bonds in N, and H₂

92 kJ of energy are required to form the bonds in NH

Which of the following substances may be responsible for acid rain?

Carbon dioxide and carbon monoxide

Sulphur dioxide and hydrogen sulphide

Which of the following processes gives a dif- ferent gaseous product from the others?

Photosynthesis in plants

Respiration in animals

Oxidation of carbon monoxide

Heating calcium carbonate

Aluminium is obtained industrially by

reducing its oxide in the blast furnace using magnesium to displace it from aqueous solution

using magnesium to displace it from aqueous solution

the electrolysis of molten cryolite

the electrolysis of molten alumina

Both glass and ceramics contain the non- metal

CSEC Chemistry Paper 1 May/June 2006 - Free CXC Past Paper with Answers

CSEC Chemistry Paper 1 May/June 2006 Questions