Ionic bonding and ionic compounds

Lithium is an alkali metal.

State which group of the periodic table contains the alkali metals.

Which of the following is a property of lithium?

A teacher adds a small piece of lithium to water containing universal indicator.

The universal indicator changes colour.

State the colour change shown by the universal indicator.

When lithium is added to water, lithium hydroxide and a gas are produced.

What is the name of the gas produced in this reaction?

Lithium hydroxide contains lithium ions, Li⁺.

Describe how a lithium atom becomes a lithium ion.

Calculate the percentage by mass of hydrogen in lithium hydroxide, LiOH.

(relative atomic masses: Li = 7, O = 16, H = 1.0)

Nitrogen reacts with hydrogen to form ammonia.

The reaction is reversible.

Complete the word equation for the reaction by adding the symbol to show that the reaction is reversible.

nitrogen + hydrogen_........ ammonia

Figure 4 shows the electronic configuration of an atom of hydrogen.

Complete the dot and cross diagram for a molecule of hydrogen, H₂.

H H

Ammonia reacts with sulfuric acid to form ammonium sulfate.

Write the word equation for this reaction.

Ammonium sulfate contains ammonium ions, NH₄⁺, and sulfate ions, SO₄^2–.

What is the formula of ammonium sulfate?

Explain why some farmers spread ammonium sulfate on their fields.

Water treatment is needed to make most sources of water suitable for drinking.

Water treatment includes the processes of chlorination, filtration and sedimentation.

Place these processes in the order that they take place during water treatment.

Some tap water contains chloride ions.

Explain, in terms of electrons, how a chlorine atom, C l, forms a chloride ion, Cl^–.

Why is chlorine added to water during water treatment?

State why tap water is not suitable for use in chemical analysis.

A student was asked to distil a sample of tap water. Figure 5 shows the apparatus the student used.

The student made an error when setting up the apparatus in Figure 5.

This error meant that pure water could not be collected in the test tube.

Explain what the student needs to change so that pure water can be collected in the test tube.

State what the student should use to heat the water.

Sodium carbonate has the formula Na₂CO₃.

Sodium carbonate contains Na⁺ ions and CO₃^2– ions.

The atomic number of sodium is 11.

What is the electronic configuration of the Na⁺ ion?

Explain why solid sodium carbonate cannot conduct electricity but a solution of sodium carbonate can conduct electricity.

Calculate the percentage by mass of sodium in sodium carbonate, Na₂CO₃.

(relative atomic masses: C = 12, O = 16, Na = 23)

percentage by mass of sodium =_........

*(c) A student has three solids, A, B and C.

The solids are sodium carbonate, powdered zinc and copper oxide, but the student does not know which solid is which.

The student reacted each solid with dilute sulfuric acid.

Figure 15 shows the student’s observations and the results of tests on any gases produced.

Use the observations and results in Figure 15 to identify which solid is which.

Your answer should include

• how each test result helps you to identify the solid

• word equations to support your answer.

Sodium carbonate has the formula Na₂CO₃.

Sodium carbonate contains Na⁺ ions and CO₃^2– ions.

The atomic number of sodium is 11.

What is the electronic configuration of the Na⁺ ion?

Explain why solid sodium carbonate cannot conduct electricity but a solution of sodium carbonate can conduct electricity.

Calculate the percentage by mass of sodium in sodium carbonate, Na₂CO₃.

(relative atomic masses: C = 12, O = 16, Na = 23)

percentage by mass of sodium =_........

This question is about the extraction of metals.

Give two advantages of obtaining metals by recycling rather than by extracting them from their metal ores.

Small amounts of some metals are extracted using displacement reactions.

In one process, zinc dust is used to precipitate cadmium metal from a solution containing cadmium ions.

cadmium ions cadmium

Explain why this displacement reaction can be described as a redox reaction.

The formula of the cadmium ion is Cd²⁺. The formula of the phosphate ion is PO₄^3–.

Which is the formula of cadmium phosphate?

One of the alternative biological methods of extracting metals from very low‑grade ores is bioleaching using bacteria.

Give one disadvantage of this method of extracting metals from low‑grade ores.

Lead is low in the reactivity series.

Describe how to obtain a sample of lead from some lead oxide in the laboratory.

In one reaction the temperature of the reaction mixture decreases.

Which word describes this type of reaction?

In an experiment, a salt is dissolved in water.

The temperature change is measured.

Figure 7 shows the apparatus that is used.

State what is used to measure the temperature change in Figure 7.

State one reason for using the piece of equipment A in Figure 7.

A student suggests putting a lid on piece of equipment B.

State why this would help to give a more accurate value for the temperature change.

Four different salts, P, Q, R and S, are dissolved in water.

Figure 8 shows the starting temperature of the water and the final temperature of the solution after the salt dissolves.

Complete the table

• to show the temperature changes when salt R and salt S dissolve

• by placing a tick (✓) in the box, on the bottom row, for the salt that absorbs the most heat energy when it dissolves.

One of the salts dissolved is barium chloride, BaCl₂.

Barium chloride contains the chloride ion, Cl^–.

Give the formula of the barium ion in barium chloride.

Figure 6 shows a poly(ethene) bottle containing substance K with one of its hazard symbols showing.

Explain a safety precaution that should be taken when using a substance with the hazard symbol shown in Figure 6.

Substance K has the formula AgNO₃. Give the name of substance K.

State one property of poly(ethene) that makes it a suitable material to make a container for storing substances.

A student tests a solid for chloride ions.

The student uses the following method.

step 1 dissolve a small amount of the solid in water

step 2 add some dilute hydrochloric acid

step 3 add a few drops of a solution of K

step 4 observe whether or not a white precipitate forms.

This method to show whether the solid contains chloride ions will not work.

Explain a change that needs to be made to step 2 to allow this method to work.

In the test for carbonate ions, the carbonate ions react with an acid.

Sodium carbonate, Na₂CO₃, is reacted with dilute hydrochloric acid.

Complete and balance the equation for this reaction.

Na₂CO₃ + 2HCl _........ +_........ +_........

The carbonate of element X has the formula X₂CO₃. The relative formula mass of this carbonate is 230.

Using this information, calculate the relative atomic mass of X.

(relative atomic masses: C = 12, O = 16)

relative atomic mass of X =_........

Magnesium is a metal.

State one physical property of magnesium.

Which element is in the same group of the periodic table as magnesium? Use the periodic table to help you answer this question.

Magnesium atoms have 12 electrons.

Complete the electronic configuration of a magnesium atom.

The electronic configuration of a chlorine atom is 2.8.7

Explain how the electronic configuration of chlorine is linked to its period in the periodic table.

1.20 g of magnesium reacts completely with 3.55 g of chlorine to form magnesium chloride.

Calculate the empirical formula of the magnesium chloride.

(relative atomic masses: Mg = 24.0, C l = 35.5)

You must show your working.

Sodium reacts with chlorine to form sodium chloride, which contains ionic bonds.

Hydrogen reacts with chlorine to form hydrogen chloride, which contains covalent bonds.

Figure 9 shows dot and cross diagrams of these compounds.

Describe the differences between an ionic bond and a covalent bond.

Magnesium carbonate has the formula MgCO₃.

Magnesium carbonate contains Mg²⁺ and CO₃²⁻ ions.

The atomic number of magnesium is 12.

What is the electronic configuration of the Mg²⁺ ion?

Explain why solid magnesium carbonate cannot conduct electricity but solid magnesium can.

Calculate the percentage by mass of magnesium in magnesium carbonate, MgCO₃.

(relative atomic masses: C = 12.0, O = 16.0, Mg = 24.0)

percentage by mass of magnesium =_........

Magnesium carbonate reacts with dilute hydrochloric acid. Water and carbon dioxide are two of the products of the reaction.

Complete the balanced equation for this reaction.

The method used to extract a metal from its ore depends on the position of the metal in the reactivity series.

Aluminium is extracted from its ore by electrolysis.

Explain why this method is used to extract aluminium from its ore.

One step in the extraction of titanium metal involves the displacement reaction between titanium chloride, TiCl₄, and magnesium.

This equation can be simplified as

Explain why this displacement reaction can be described as a redox reaction.

The formula of the sulfate ion is SO²⁻₄.

Which of the following is the formula of titanium sulfate containing the Ti⁴⁺ ion?

Phytoextraction is an alternative biological method that can be used to extract metals from very low-grade ores.

Give one disadvantage of phytoextraction as a method of extraction of metals.

Copper is low down in the reactivity series and can be obtained from copper oxide.

Devise a simple method to obtain a sample of copper from copper oxide in the laboratory.

An ion of element X can be represented as

This ion of element X has 54 electrons.

Calculate the number of protons and the number of neutrons in this ion.

A sample of silicon contains isotopes.

State, in terms of subatomic particles, how atoms of these isotopes are the same.

This sample of silicon contains three isotopes.

92% of the atoms are silicon-28 5% of the atoms are silicon-29 3% of the atoms are silicon-30

Calculate the relative atomic mass of silicon in this sample.

relative atomic mass =_........

*(c) Figure 6 shows some properties of three substances, A, B and C.

Deduce, using the information in Figure 6, the structure and bonding of substances A, B and C, explaining their properties in terms of their structure and bonding.

This question is about potassium and zinc.

Which of the following temperatures is most likely to be the melting point of potassium?

Explain how the electronic configuration of an atom of potassium is related to its position in the periodic table.

Potassium reacts with oxygen to form potassium oxide.

Describe the test to show that a gas is oxygen.

Potassium oxide is ionic.

Write the electronic configurations for the ions in potassium oxide, K₂O.

Figure 6 shows two gas syringes connected by a glass tube.

Inside the glass tube there are some pieces of zinc. Zinc reacts with oxygen at a temperature of over 225 °C. Not all the oxygen reacts at once, the oxygen reacts only when in contact with the zinc.

Devise a plan to find the volume of oxygen contained in a known volume of air, using the apparatus shown in Figure 6.

Figure 11 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes.

Hydrogen is produced at the negative electrode during electrolysis.

Describe the test to show the gas is hydrogen.

What is the name of gas X that forms at the positive electrode?

State what is meant by the term electrolysis.

The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm³ of solution.

Calculate the concentration of this solution in g dm⁻³.

Give your answer to three significant figures.

concentration =_........ g dm

The ions present in sodium sulfate are

Write the formula of sodium sulfate using this information.

In Figure 11, the gases given off at the electrodes are collected in test-tubes. However, the actual volume of gases cannot be measured using these test-tubes.

Suggest what apparatus could be used in place of the test-tubes in Figure 11 to measure the volume of gases given off.

State what could be added into the circuit to show a current is flowing during electrolysis.

Figure 3 shows the apparatus that can be used to electrolyse sodium sulfate solution using inert electrodes.

Hydrogen is produced at the negative electrode during electrolysis.

Describe the test to show the gas is hydrogen.

What is the name of gas X that forms at the positive electrode?

State what is meant by the term electrolysis.

The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm³ of solution.

Calculate the concentration of this solution in g dm⁻³.

Give your answer to three significant figures.

concentration =_........ g dm

The ions present in sodium sulfate are

Write the formula of sodium sulfate using this information.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

What are the elements in group 1 of the periodic table called?

Figure 14 shows the melting points and boiling points of elements in group 7 of the periodic table.

Give, using Figure 14, the boiling point of bromine.

State which two elements from Figure 14 are solids at room temperature.

An atom of potassium has atomic number 19 and mass number 39.

Give the electronic configuration of this potassium atom.

This potassium atom forms the ion K⁺.

Which row shows the number of protons and the number of neutrons in this potassium ion, K⁺?

Potassium and caesium are in the same group of the periodic table.

Explain, in terms of electrons, why potassium and caesium are in the same group.

Fluorine boils at –188C. There are forces between fluorine molecules.

Explain, in terms of these forces, why the boiling point of fluorine is low.

Potassium reacts with fluorine to form potassium fluoride. Potassium fluoride is a solid.

Complete the balanced equation for this reaction and add the state symbols.

Using the letters A, E, G, J, X and Z

give the letters of the two elements that are non-metals

give the letters of two elements in period 2

give the letter of an element that normally forms an ion with a charge of +1.

Element E has an atomic number of 5. In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.

Explain, in terms of subatomic particles, what is meant by the term isotopes.

All atoms of element E in this sample contain

Element X has an atomic number of 18.

State the electronic configuration of an atom of element X.

In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.

Calculate the empirical formula of this compound. (relative atomic masses: A = 7, G = 16)

You must show your working.

An aluminium atom has the atomic number 13 and the mass number 27.

Which row shows the numbers of subatomic particles present in an

Magnesium burns in excess oxygen to form magnesium oxide. The balanced equation for this reaction is

Starting with 1.35 g of magnesium, calculate the maximum mass of magnesium oxide that could be formed in this reaction. (relative atomic masses: O = 16.0, Mg = 24.0)

You must show your working.

Chlorine reacts with hydrogen to form hydrogen chloride.

Write the balanced equation for this reaction.

*(d) Sodium chloride is an ionic compound, containing sodium ions, Na⁺, and chloride ions, Cl^–.

Figure 15 shows the electronic configuration of sodium and chlorine.

Explain how sodium and chlorine atoms form the ions in sodium chloride and how the ions are arranged in the solid sodium chloride.

You may wish to use diagrams in your answer.

An aluminium atom has the atomic number 13 and the mass number 27.

Which row shows the numbers of subatomic particles present in an

Magnesium burns in excess oxygen to form magnesium oxide. The balanced equation for this reaction is

Starting with 1.35 g of magnesium, calculate the maximum mass of magnesium oxide that could be formed in this reaction. (relative atomic masses: O = 16.0, Mg = 24.0)

You must show your working.

Chlorine reacts with hydrogen to form hydrogen chloride.

Write the balanced equation for this reaction.

Sodium reacts with chlorine to form sodium chloride.

The electronic configuration of the sodium atom is 2.8.1 and the electronic configuration of the chlorine atom is 2.8.7.

Give the electronic configurations of the ions formed.

(a) Salts of metals can be prepared by reacting the metal with an acid to produce the salt and hydrogen.

Describe the test to show the gas is hydrogen.

Nickel is a metal.

Explain how the structure of a nickel atom, Ni, changes when it forms a nickel ion, Ni²⁺.

A nickel sulfate solution is made by dissolving 23.5 g of nickel sulfate to make 250 cm³ of solution.

Calculate the concentration of the solution in g dm⁻³.

concentration =_........ g dm

Excess solid nickel carbonate is added to dilute sulfuric acid in a beaker.

nickel sulfuric nickel carbon

Nickel sulfate is formed in solution.

Describe how a sample of pure, dry nickel sulfate crystals can be obtained from the mixture of nickel sulfate solution and excess solid nickel carbonate in the beaker.