national 5 chemistry exam revision

National 5 ChemistryExam Revision

Chemical Changes

Reaction Rates

1. A student investigated the reaction between dilute hydrochloric acid and sodium carbonate. One experiment involved measuring the volume of carbon dioxide produced when solid sodium carbonate was used.

Time/s 0 10 30 40 50 60 70Volume CO2/cm3 0 10 25 32 41 49 49

a) Calculate the average rate in cm3/s of carbon dioxide produced between 10 and 40 seconds.

b) Calculate the average rate in cm3/s of carbon dioxide produced in the first 40seconds.

c) When did the reaction finish?

Copy and complete the diagram to show how the carbon dioxide gas could be collected from the reaction of calcium carbonate chips and sulphuric acid.

Atomic Structure & Bonding

The table shows the numbers of protons, electrons and neutrons in four particles, W, X, Y and Z.

Which pair of particles are isotopes?

A. W and X B. W and Y C. X and Y D. Y and Z

Bromine has two isotopes. One has a mass number of 81 and the other has a mass number of 79. The relative atomic mass of bromine is 80.

What does this tell you about the percentage of each isotope in bromine?

Chlorine has two isotopes. One has a mass number of 35 and the other has a mass number of 37. The relative atomic mass of chlorine is 35.5.

Which isotope of chlorine is most abundant in the sample?

Find the number of protons, neutrons and electrons in each of the following;

1.

2.

3.

4.

Which substance exists as diatomic molecules

A. Sodium chlorideB. Nitrogen monoxideC. Silicon tetrachlorideD. Sulfur dioxide

Solid ionic compounds do not conduct electricity because;

A. The ions are not free to move

B. The electrons are not free to move

C. Solid substances never conduct electricity

D. There are no charged particles in ionic compounds

Draw a diagram to show how the outer electrons are shared in a molecule of;

1. Hydrogen chloride2. Hydrogen sulfide3. Nitrogen fluoride4. Water5. Methane

Which of the following diagrams could be used to represent the structure of a covalent network?

The table gives information about some substances. Substance Melting

point/0CBoiling

point/ 0CConduction as

A solid A liquid

A 1890 3380 Yes YesB 963 1560 No YesC 1455 2730 Yes YesD -183 -164 No NoE 1700 2230 No NoF 712 1418 No Yes

(a) Identify the two ionic compounds. (b) Identify the covalent network(c) Identify the covalent molecular compound(d) Identify the substance which is a gas at room temperature

(210C)

A substance X, has a melting point of 996 C and a ⁰boiling point of 1704 C. It only conducts electricity ⁰when molten or when dissolved in water.

The structure of X is likely to be

A. IonicB. MetallicC. Covalent networkD. Covalent molecular

Formula and reactant quantities

Write the chemical formula for;

1. Sodium fluoride2. Magnesium carbide3. Calcium carbonate4. Potassium permanganate5. Cobalt (II) chloride6. Ammonium nitrate

Write the ionic formula for;

1. Lithium iodide2. Magnesium oxide3. Copper (II) carbonate4. Calcium sulphite5. Beryllium hydroxide6. Ammonium phosphate

In vanadium oxide, VaO2, what is the valency of vanadium?

A 1B 2C 3D 4

What is the charge on the chloride ion in SnCl4?

A 1+B 1–C 4+D 4–

Acids & Alkalis

Precipitation is when two solutions react to form an insoluble product. Which of the following pairs of solutions would react together to produce a precipitate?A. Silver (I) nitrate +

sodium chlorideB. Copper (II) sulphate +

sodium nitrateC. Magnesium chloride +

lithium nitrateD. Barium chloride +

potassium nitrate

When barium nitrate solution is mixed with sodium sulphate solution, the name of the precipitate formed is

a. barium chlorideb. barium sulphatec. sodium chlorided. sodium nitrate

Which of the following gases would dissolve in water to produce an alkaline solution?

A. Carbon dioxideB. Nitrogen dioxideC. AmmoniaD. Methane

Which of the following oxides would dissolve in water to produce an acidic solution?(You may wish to consult your data booklet)

A. sulphur dioxideB. iron (III) oxideC. copper (II) oxideD. sodium oxide

Which of the following is not a salt?A. Sodium chlorideB. Lithium sulphateC. Potassium hydroxideD. Copper (II) nitrate

Which of the following reactions would not result in the formation of a salt?A. Acid + alkaliB. Acid + reactive metalC. Acid + alcoholD. Acid + carbonate

Name the product (s) of the following neutralisation reactions;

a. Magnesium and hydrochloric acidb. Potassium hydroxide and sulfuric acidc. Magnesium carbonate and hydrochloric acidd. Calcium carbonate and nitric acide. Ammonia and sulfuric acid

Which of the following statements correctly describes the concentration of H+ (aq) and OH- (aq) ions in an acidic substance when compared to pure water?

A. The concentration of H+ (aq) and OH- (aq)ions are zero.

B. The concentration of H+ (aq) and OH- (aq)ions are equal.

C. The concentration of H+ (aq) is higher than OH-

(aq) ions.D. The concentration of H+ (aq) is lower than OH-

(aq) ions.

Which line in the table correctly describes what happens to a dilute solution of hydrochloric acid when water is added to it?