gcseprep.com · web view2020/04/02 · many everyday substances can be classified as acids, bases...

2.1 Bonding structure - Chemical bonds - Standard demand – Questions

Q1. This question is about calcium.

(a) What type of compound is calcium oxide?

Tick one box.

An acid

A base

A carbonate

A salt

(1)

(b) Ionic compounds, such as calcium oxide, have high melting points.

Complete the sentences. Use words from the box.

bonds forces ions layers

Calcium oxide has a giant ionic lattice in which there are strong electrostatic

______________________ of attraction in all directions.(1)

(c) The figure below shows the electronic structure of an oxygen atom and a calcium atom.

Describe how the calcium atom and the oxygen atom forms calcium oxide.

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You should give the charge on each ion formed.

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(Total 6 marks)

Q2.Three substances are all solid at room temperature.

The table describes tests and the result of each test on the three substances.

SubstanceEffect of large force applied

Effect of heating gently at first, then strongly

Effect of passing electricity through solid

Effect of passing electricity through liquid

A Breaks into many pieces

Easily melts and then boils

Does not conduct

Does not conduct

B Breaks into many pieces No change Does not

conduct Conducts

C Becomes thinner No change Conducts Conducts

(a) The covalent bonds in the molecules are not overcome when substance A is heated.

What forces are overcome when substance A melts?

___________________________________________________________________(1)

(b) What could substance A be?

Tick one box.

Graphite

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Iron

Sodium chloride

Sulfur

(1)

(c) Suggest why substance B conducts electricity as a liquid but does not conduct electricity as a solid.

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(d) Suggest why substance C becomes thinner when a large force is applied.

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(e) What could substance C be?

Tick one box.

Copper

Diamond

Iodine

Magnesium oxide

(1)(Total 8 marks)

Q3.This question is about fluorine.

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(a) Figure 1 shows the arrangement of electrons in a fluorine atom.

(i) In which group of the periodic table is fluorine?

Group _______________________________(1)

(ii) Complete the table below to show the particles in an atom and their relative masses.

Name of particle Relative mass

Proton

Neutron 1

Very small

(2)

(iii) Use the correct answer from the box to complete the sentence.

alkalis alloys isotopes

Atoms of fluorine with different numbers of neutrons are

called ________________ .(1)

(b) Sodium reacts with fluorine to produce sodium fluoride.

(i) Complete the word equation for this reaction.

sodium + ___________________ → ____________________(1)

(ii) Complete the sentence.

Substances in which atoms of two or more different elements are chemically

combined are called _____________________ .(1)

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(iii) The relative formula mass (Mr) of sodium fluoride is 42.

Use the correct answer from the box to complete the sentence.

ion mole molecule

The relative formula mass (Mr), in grams, of sodium fluoride is one

_______________ of the substance.(1)

(iv) Figure 2 shows what happens to the electrons in the outer shells when a sodium atom reacts with a fluorine atom.

The dots (•) and crosses (×) represent electrons.

Use Figure 2 to help you answer this question.

Describe, as fully as you can, what happens when sodium reacts with fluorine to produce sodium fluoride.

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______________________________________________________________(4)

(v) Sodium fluoride is an ionic substance.

What are two properties of ionic substances?

Tick (✔) two boxes.

Dissolve in water

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Gas at room temperature

High melting point

Low boiling point

(2)(Total 13 marks)

Q4.This question is about magnesium.

(a) (i) The electronic structure of a magnesium atom is shown below.

Use the correct answer from the box to complete each sentence.

electrons neutrons protons shells

The nucleus contains protons and ____________________ .

The particles with the smallest relative mass that move around the nucleus are

called ____________________ .

Atoms of magnesium are neutral because they contain the same number of

electrons and ____________________ .(3)

(ii) A magnesium atom reacts to produce a magnesium ion.

Which diagram shows a magnesium ion?

Tick ( ) one box.

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(1)

(b) Magnesium and dilute hydrochloric acid react to produce magnesium chloride solution and hydrogen.

Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)

(i) State two observations that could be made during the reaction.

1. ____________________________________________________________

______________________________________________________________

2. ____________________________________________________________

______________________________________________________________(2)

(ii) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Describe a method for making pure crystals of magnesium chloride from magnesium and dilute hydrochloric acid.

In your method you should name the apparatus you will use.

You do not need to mention safety.

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______________________________________________________________(6)

(Total 12 marks)

Q5.(a) The diagram shows an atom of magnesium and an atom of chlorine.

Magnesium Chlorine

Describe, in terms of electrons, how magnesium atoms and chlorine atoms change into ions to produce magnesium chloride (MgCl2).

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(b) Calculate the relative formula mass (Mr) of magnesium chloride (MgCl2).

Relative atomic masses (Ar): magnesium = 24; chlorine = 35.5

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Relative formula mass (Mr) = ________(2)

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(Total 6 marks)

Q6.A student investigated the conductivity of different concentrations of sodium chloride solution.The student set the apparatus up as shown in Figure 1.

Figure 1

The student measured the conductivity of the pure water with a conductivity meter.

The reading on the conductivity meter was zero.

(a) The student:

• added sodium chloride solution one drop at a time • stirred the solution • recorded the reading on the conductivity meter.

The student’s results are shown in the table below.

Number of drops ofsodium chloride

solutionadded

Relative conductivityof solution

0 0

1 100

2 120

3 310

4 400

5 510

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6 590

7 710

8 800

(i) The student plotted the results on the grid shown in Figure 2.

Plot the four remaining results.

Draw a line of best fit, ignoring the anomalous result.

Figure 2

Number of drops of sodium chloride added(3)

(ii) One of the points is anomalous.

Suggest one error that the student may have made to cause the anomalous result.

______________________________________________________________

______________________________________________________________(1)

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(iii) The student wanted to compare the conductivity of sodium chloride solution with the conductivity of potassium chloride solution.

State one variable he should keep constant when measuring the conductivity of the two solutions.

______________________________________________________________(1)

(b) (i) Explain, in terms of bonding, why pure water does not conduct electricity.

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______________________________________________________________(2)

(ii) Explain why sodium chloride solution conducts electricity.

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(iii) After he had added sodium chloride solution, the student noticed bubbles of gas at the negative electrode.

Complete the sentence.

The gas produced at the negative electrode is __________________(1)

(Total 10 marks)

Q7.In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.

Explain why chlorine (Cl2) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature.

Chlorine Sodium chloride

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Include a description of the bonding and structure of chlorine and sodium chloride in your answer.

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Extra space _____________________________________________________________

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_______________________________________________________________________(Total 6 marks)

Q8.Ammonia is produced from nitrogen and hydrogen.

The equation for this reaction is:

(a) (i) A company wants to make 6.8 tonnes of ammonia.

Calculate the mass of nitrogen needed.

Relative atomic masses (Ar): H = 1; N = 14

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Mass of nitrogen = _____________________ tonnes(3)

(ii) The company expected to make 6.8 tonnes of ammonia.

The yield of ammonia was only 4.2 tonnes.

Calculate the percentage yield of ammonia.

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Percentage yield of ammonia = ________________ %(2)

(iii) Use the equation above to explain why the percentage yield of ammonia was less than expected.

______________________________________________________________

______________________________________________________________(1)

(b) Complete the diagram to show the arrangement of the outer shell electrons of the nitrogen and hydrogen atoms in ammonia.

Use dots (●) and crosses (x) to represent the electrons.

(2)

(c) Ammonia dissolves in water to produce an alkaline solution.

(i) Which ion makes ammonia solution alkaline?

______________________________________________________________(1)

(ii) Name the type of reaction between aqueous ammonia solution and an acid.

______________________________________________________________(1)

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(iii) Name the acid needed to produce ammonium nitrate.

______________________________________________________________(1)

(iv) The reaction of ammonia with sulfuric acid produces ammonium sulfate.

Use the formulae of the ions on the Chemistry Data Sheet.

Write the formula of ammonium sulfate.

______________________________________________________________(1)

(Total 12 marks)

Q9.Sodium chloride is a raw material.

(a) The electronic structure of a sodium atom is shown below.

Complete the diagram for the electronic structure of a chlorine atom. A chlorine atom has 17 electrons.

(1)

(b) When sodium and chlorine react to form sodium chloride they form sodium ions (Na+

) and chloride ions (Cl– ).

How does a sodium atom change into a sodium ion?

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(c) The diagram shows apparatus used in a school laboratory for the electrolysis of sodium chloride solution.

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The solution contains sodium ions (Na+), chloride ions (Cl– ), hydrogen ions (H + ) and hydroxide ions (OH– ).

(i) Why do chloride ions move to the positive electrode?

______________________________________________________________(1)

(ii) Name the gas formed at the negative electrode.

______________________________________________________________(1)

(d) Chlorine and chlorine compounds are used to bleach wood pulp that is used to make paper.

The article below is from a newspaper.

Local people have been protesting outside a paper factory. They say:‘We want the company to stop using chlorine compounds. Chlorine compoundsrelease poisons into the environment. The company should use safer compounds.’

The company replied:‘Chlorine has been used safely for many years to treat drinking water. Only tinyamounts of chlorine are released, which cause no harm. Using other compounds willbe more expensive and may put us out of business.’

(i) Why are some local people worried about the use of chlorine compounds?

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(ii) Why might other local people want the company to continue to use chlorine compounds?

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(1)

(iii) It is decided to have an inquiry.Why should this be done by independent scientists?

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(Total 8 marks)

Q10.(a) Write a balanced symbol equation for the reaction between magnesium (Mg) and

oxygen (O2) to form magnesium oxide (MgO).

___________________________________________________________________(1)

(b) The diagram shows the electronic structure of a magnesium atom.The atomic (proton) number of magnesium is 12.

Magnesium atom

Draw a similar diagram to show the electronic structure of an oxygen atom.The atomic (proton) number of oxygen is 8.

(1)

(c) Magnesium ions and oxide ions are formed when magnesium reacts with oxygen.

The diagram shows the electronic structure of an oxide ion.

Oxide ion

Draw a similar diagram to show the electronic structure of a magnesium ion.

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(1)

(d) Magnesium oxide is a white solid with a high melting point.

Explain how the ions are held together in solid magnesium oxide.

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(e) Indigestion tablets can be made from magnesium oxide. The magnesium oxide neutralises some of the hydrochloric acid in the stomach.

Complete the word equation for the reaction between magnesium oxide and hydrochloric acid.

hydrochloric acid + magnesium oxide → ___________ + water.(1)

(Total 6 marks)

Q11.Hydrogen chloride (HCl) can be made by the reaction of hydrogen (H2) with chlorine (Cl2).

(a) The diagrams represent molecules of hydrogen and chlorine.

Draw a similar diagram to represent a molecule of hydrogen chloride (HCl).You need show only the outer energy level (shell) electrons.

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(1)

(b) The word equation for the reaction of hydrogen with chlorine is shown below.

hydrogen + chlorine → hydrogen chloride

Write a balanced symbol equation for this reaction.

______________________________________________________________(2)

(c) Hydrogen chloride gas reacts with magnesium to form the ionic compound called magnesium chloride. Use the table of ions on the Data Sheet to help you to write the formula of magnesium chloride.

______________________________________________________________(1)

(d) Why does magnesium chloride have a much higher melting point than hydrogen chloride?

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(Total 6 marks)

Q12.(a) A tin of red kidney beans contains calcium chloride as a firming agent.

Calcium chloride is an ionic compound which contains calcium ions (Ca2+) and chloride ions (Cl–).

(i) The diagram on the left represents the electronic structure of a chlorine atom.

Complete a similar diagram on the right to represent a chloride ion.

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(2)

(ii) Explain how a calcium atom changes into a calcium ion which has a 2+ charge.

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______________________________________________________________(2)

(b) Cola drinks contain phosphoric acid, H3PO4. The two equations show how phosphoric acid can be made from phosphorus.

Balance these two equations.

(i) P4 + ____ O2 → P4O10

(1)

(ii) P4O10 + ________ H2O → 4H3PO4

(1)(Total 6 marks)

Q13.Many everyday substances can be classified as acids, bases or salts. For example, car batteries contain sulphuric acid, oven cleaners contain sodium hydroxide and table salt contains sodium chloride.

(a) A solution of each of these substances was tested with universal indicator.

Solution Colour of universal indicator

Sulphuric acid (H2SO4) red

Sodium hydroxide (NaOH) purple

Sodium chloride (NaCl) green

(i) Explain how these universal indicator colours and the corresponding pH values could be used to identify each of these solutions.

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______________________________________________________________(3)

(ii) Name and give the formula of the ion which causes the solution to be acidic.

Name of ion _________________________________________________

Formula of ion _________________________________________________(2)

(b) Sodium chloride can be made by reacting sodium hydroxide with hydrochloric acid in the presence of an indicator.

(i) What is the name of this type of reaction?

______________________________________________________________(1)

(ii) Write a balanced chemical equation for this reaction.

_______(aq) + _______(aq) → _______(aq) + _______(l)(2)

(c) The atomic number for sodium is 11 and for chlorine is 17.

(i) Complete the diagrams to show the electron arrangements for a sodium atom and a chlorine atom.

(2)

(ii) These atoms form different particles by one electron transferring from the sodium atom to the chlorine atom. What is the name given to the particles formed?

______________________________________________________________(1)

(iii) Why do these sodium and chloride particles bond?

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______________________________________________________________(1)

(d) Sodium chloride solution is electrolysed to form three products, hydrogen, chlorine and sodium hydroxide.

Describe how each of these products are formed.

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(Total 15 marks)

Q14.This question is about sodium chloride (common salt) which is an important chemical.

Sodium chloride can be made by burning sodium in chlorine gas.

(a) Balance the symbol equation for the reaction of sodium with chlorine.

Na(s) + Cl2(g) → NaCl(s)

(1)

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(b) (i) Complete the diagrams below to show the electronic structures of a sodium and a chlorine atom. (Atomic number of sodium = 11 and chlorine = 17.)

(3)

(ii) When sodium reacts with chlorine the sodium atoms are changed into sodium ions (Na+) and the chlorine atoms are changed into chlorine ions (Cl–).

Explain how:

1. a sodium atom changes into a sodium ion;

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2. a chlorine atom changes into a chloride ion.

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(c) The element potassium is in the same group of the Periodic Table as sodium. Potassium reacts with chlorine to make potassium chloride which is sometimes used instead of common salt in cooking.

(i) Predict the formula of potassium chloride.

______________________________________________________________(1)

By reference to the electronic structures of potassium and sodium explain:

(ii) Why the reaction of potassium with chlorine is similar to the reaction of sodium with chlorine.

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(d) The electrolysis of sodium chloride solution is an important industrial process. The diagrams below show two experiments set up during an investigation of the electrolysis of sodium chloride.

(i) What would be the reading on the ammeter in experiment 1?

__________________________ A

(ii) Explain your answer.

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(e) The equations below show the reactions which take place in experiment 2.

H2O(1) → H+(aq) + OH– (aq)

2H+(aq) + 2e– → H2(g)

2Cl–(aq) – 2e– → Cl2(g)

(i) Which substance provides hydrogen ions?

______________________________________________________________(1)

(ii) Name the product formed at:

(A) the positive electrode;

______________________________________________________________

(B) the negative electrode.

______________________________________________________________(1)

(Total 15 marks)

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Q15.Fluorine is a very useful element. It is placed in group 7 of the Periodic Table.

Use your knowledge of the elements in group 7 to help you answer these questions. You may find that information in the Data Sheet may help you with this question.

(a) Name another element in group 7 of the Periodic Table.

___________________________________________________________________(1)

(b) Cylinders filled with fluorine molecules are commercially available. What would you expect the formula of a fluorine molecule to be?

___________________________________________________________________(1)

(c) Fluoride ions are added to drinking water to help prevent tooth decay. What is the charge on fluoride ions in the water?

___________________________________________________________________(1)

(d) Fluorine reacts with the non-metal sulphur to make sulphur hexafluoride (SF6).

(i) What type of bonding would you expect in sulphur hexafluoride?

______________________________________________________________(1)

(ii) Explain the reason for your answer to part (i).

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(Total 5 marks)

Q16.The hydrogen halides (hydrogen fluoride, hydrogen chloride, hydrogen bromide and hydrogen iodide) are important chemicals.

The diagram below represents a molecule of hydrogen chloride.

(i) What type of particles are represented by the crosses (X)?

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___________________________________________________________________(1)

(ii) What type of chemical bond holds the atoms in this molecule together?

___________________________________________________________________ (1)

(iii) Would you expect hydrogen chloride to be a gas, a liquid or a solid, at room temperature and pressure? Explain your answer.

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(Total 5 marks)

Q17.Diesel oil is obtained from crude oil. It can be used as a fuel for car engines. The diagram below represents a compound found in diesel oil.

(a) What is the formula of this compound?

___________________________________________________________________(1)

(b) Each of the lines on the diagram above represents a covalent bond.

What is a covalent bond?

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(Total 3 marks)

Q18.Calcium and magnesium are elements. They are found in the Earth’s crust as compounds, often carbonates and sulphates. Magnesium is also found as its chloride.

(a) Calcium and magnesium are in the same Group in the Periodic Table.State which Group this is.

___________________________________________________________________(1)

(b) Use the Data Sheet to help you to answer this question.

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(i) Write the chemical formula of magnesium chloride.

______________________________________________________________(1)

(ii) Name the type of bonding in magnesium chloride.

______________________________________________________________(1)

(Total 3 marks)

Q19.Sodium chloride is an ionic compound.

(Total 2 marks)

Q20.(a) Magnesium burns in oxygen, forming magnesium oxide.

This equation represents the reaction.

Mg (s) + O2 (g) → MgO (s)

(i) Balance the equation.(1)

(ii) Give the meaning of the state symbols (s) and (g).

(s) _______________________

(g) _______________________(2)

(b) Use the Formulae of Some Common Ions table on the Data Sheet to help you to answer this question.

Magnesium also reacts with chlorine to form magnesium chloride.

Give the formula of magnesium chloride _________________________________(1)

(Total 4 marks)

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Q21.(a) A piece of lithium is placed on the surface of some water in a beaker.

Hydrogen is given off.Lithium hydroxide is also formed.

Write a word equation for this reaction.

___________________________________________________________________(2)

(b) The diagram shows the structure of a molecule of methane.

Write down everything that this diagram tells you about a methane molecule.

To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words.

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(Total 6 marks)

Q22.(a) Atoms are made of sub-atomic particles. Complete the six spaces in the table.

Name of sub-atomic particle

Relative mass Relative charge

_________________

___________

Neutron ___________ ____________

_________________ 1 ____________

(3)

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(b) Complete the spaces in the sentences.

(i) The atomic number of an atom is the number of ___________________ in its

nucleus and is equal to the number of ___________________________ if the

atom is not charged.(1)

(ii) The mass number of an atom is the total number of _________________ and

___________________ in its nucleus.(1)

(c) The table gives information about the atoms of three elements.

Name ofelement

Chemicalsymbol

Number of electrons in:

1st

shell2nd

shell3rd

shell

Fluorine F 2 7 0

Neon Ne 2 8 0

Sodium Na 2 8 1

Two of these elements can react together to form a chemical compound.

(i) What is the name and the formula of this compound?

Name __________________________ Formula _____________________(2)

(ii) What type of bonding holds this compound together?

______________________________________________________________(1)

(iii) Explain, in terms of electron transfer, how the bonding occurs in this compound.

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(Total 10 marks)

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Q23.Part of the Periodic Table showing the symbols for the first twenty elements is given below.

(a) Draw diagrams showing the arrangement of electrons (electronic structures) in:

(i) an aluminium atom;

(ii) a chlorine atom.

(2)

(b) (i) Use electronic structures to help you show why the formula of sodium oxide is Na2O.

(3)

(ii) State why the formation of sodium ions is classified as an oxidation.

______________________________________________________________

______________________________________________________________(1)

(Total 6 marks)

Q24.

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Magnesium oxide is a compound, made up of magnesium ions and oxide ions.

(a) What is the charge on each magnesium ion? ______________________________(1)

(b) Explain how the magnesium ions get this charge.

___________________________________________________________________

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___________________________________________________________________(2)

(Total 3 marks)

Q25.Chlorine will combine with the non-metal element, carbon, to form this molecular compound.

(a) What is the type of bond in this molecule?

___________________________________________________________________(1)

(b) Explain how these bonds are formed. (You may use a diagram).

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(2)

(Total 3 marks)

Q26.(a) The chart shows the reactions of the metal calcium with water, oxygen and dilute

hydrochloric acid.

Name (i) solution A _________________________________________________

(ii) solid B ___________________________________________________

(iii) gas C ____________________________________________________(3)

(b) The diagrams below show the electronic structure of an atom of calcium and an atom of oxygen.

Describe fully what happens to its electrons when:

(i) a calcium atom forms a calcium ion. State the charge on the calcium ion formed.

______________________________________________________________

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______________________________________________________________(3)

(ii) an oxygen atom forms an oxygen ion. State the charge on the oxygen ion formed.

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______________________________________________________________(3)

(c) Calcium oxide is an ionic compound. Why do ionic compounds have high melting points?

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(Total 11 marks)

Q27.The diagram shows one molecule of the compound ammonia.

Write down everything that the diagram tells you about each molecule of ammonia.

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_______________________________________________________________________(Total 4 marks)

Q28.(a) The diagrams below show the electronic structure of a magnesium atom and a

magnesium ion.

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What is the charge on the magnesium ion? _______________________________(2)

(b) Calcium bromide has the formula CaBr2.

What does this tell you about the ions in this compound?

___________________________________________________________________

___________________________________________________________________(2)

(Total 4 marks)

Q29.Lithium chloride can be used to colour flames dark red.

By Alchimista (Own work) [CC-BY-SA-3.0] via Wikimedia Commons

(a) A chlorine atom has 17 electrons.

Complete the diagram to show the electronic structure of a chlorine atom.

(1)

(b) Lithium chloride (LiCl) can be made by reacting lithium with chlorine.

The electronic structure of a lithium atom is shown below.

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Describe what happens to a lithium atom when the atom reacts with chlorine.

___________________________________________________________________

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___________________________________________________________________(3)

(Total 4 marks)

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gcseprep.com · web view2020/04/02 · many everyday substances can be classified as acids, bases...

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