National 5 Chemistry Exam 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 10 30 40 50 60 70 Volume CO2/cm3 25 32 41 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 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.

Solid ionic compounds do not conduct electricity because; The ions are not free to move The electrons are not free to move Solid substances never conduct electricity There are no charged particles in ionic compounds Which substance exists as diatomic molecules Sodium chloride Nitrogen monoxide Silicon tetrachloride Sulfur dioxide

Draw a diagram to show how the outer electrons are shared in a molecule of; Hydrogen chloride Hydrogen sulfide Nitrogen fluoride Water Methane

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

The table gives information about some substances. Melting point/0C Boiling point/ 0C Conduction as A solid A liquid A 1890 3380 Yes B 963 1560 No C 1455 2730 D -183 -164 E 1700 2230 F 712 1418 Identify the two ionic compounds. Identify the covalent network Identify the covalent molecular compound Identify the substance which is a gas at room temperature (210C)

A substance X, has a melting point of 996⁰C and a boiling point of 1704⁰C. It only conducts electricity when molten or when dissolved in water. The structure of X is likely to be Ionic Metallic Covalent network Covalent molecular

Formula and reactant quantities

Write the chemical formula for; Sodium fluoride Magnesium carbide Calcium carbonate Potassium permanganate Cobalt (II) chloride Ammonium nitrate

Write the ionic formula for; Lithium iodide Magnesium oxide Copper (II) carbonate Calcium sulphite Beryllium hydroxide Ammonium phosphate

What is the charge on the chloride ion in SnCl4? A 1+ B 1– C 4+ D 4– In vanadium oxide, VaO2, what is the valency of vanadium? A 1 B 2 C 3 D 4

Acids & Alkalis

Precipitation is when two solutions react to form an insoluble product 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? Silver (I) nitrate + sodium chloride Copper (II) sulphate + sodium nitrate Magnesium chloride + lithium nitrate Barium chloride + potassium nitrate When barium nitrate solution is mixed with sodium sulphate solution, the name of the precipitate formed is barium chloride barium sulphate sodium chloride sodium nitrate

Which of the following oxides would dissolve in water to produce an acidic solution? (You may wish to consult your data booklet) sulphur dioxide iron (III) oxide copper (II) oxide sodium oxide Which of the following gases would dissolve in water to produce an alkaline solution? Carbon dioxide Nitrogen dioxide Ammonia Methane

Which of the following reactions would not result in the formation of a salt? Acid + alkali Acid + reactive metal Acid + alcohol Acid + carbonate Which of the following is not a salt? Sodium chloride Lithium sulphate Potassium hydroxide Copper (II) nitrate

Name the product (s) of the following neutralisation reactions; Magnesium and hydrochloric acid Potassium hydroxide and sulfuric acid Magnesium carbonate and hydrochloric acid Calcium carbonate and nitric acid 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? The concentration of H+ (aq) and OH- (aq)ions are zero. The concentration of H+ (aq) and OH- (aq)ions are equal. The concentration of H+ (aq) is higher than OH-(aq) ions. 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?