CIE iGCSE Co-Ordinated Science C9.4 Reactivity series Exam Style Questions Paper 3
Question
A student investigates the properties of five materials:
copper ice iron plastic wood
Each material is a block with the dimensions shown in Fig. 3.1.
(a) (i) State the two materials that are good thermal conductors.
(ii) State the two materials that are good electrical conductors.
(iii) State the material that a magnet attracts.
(b) The mass of the block of wood is 39g.
Use information from Fig. 3.1 to calculate the density of the block of wood.
State the units of your answer.
density = ……………………………… units ………..
(c) The block of ice melts and turns to water.
Fig. 3.2 shows the arrangement of particles in ice and in water.
Explain, in terms of the arrangement of particles, why diagram A represents ice and diagram B represents water.
(d) When the plastic block is rubbed with a cloth an electrostatic charge is produced.
State the particles that are transferred when the block is rubbed with the cloth.
▶Answer/Explanation
Ans:
3(a)(i) copper and iron ;
3(a)(ii) copper and iron ;
3(a)(iii) iron ;
3(b) volume = 3 × 4 × 5 = 60 cm3 ;
density = mass / volume (in any form) or 39 / 60 ;
= 0.65 ;
g/cm3 ;
3(c) ice – particles arranged regularly
and
water – particles arranged irregularly ;/.,
3(d) electrons ;
Question
(a) A student investigates the reaction between magnesium and dilute sulfuric acid.
During the reaction, hydrogen gas and a salt are made.
(i) Complete the word equation for this reaction.
(ii) The reaction is exothermic.
Describe two observations which show that a chemical reaction occurs between magnesium and dilute sulfuric acid.
………………………………………………………………………………………………………………………….
………………………………………………………………………………………………………………………….
(iii) The hydrogen made in the reaction exists as molecules of hydrogen, H$_{2}$.
Draw a dot-and-cross diagram to show the bonding in a molecule of hydrogen, H$_{2}$.
(b) The formula of sulfuric acid is H$_{2}$SO$_{4}$.
(i) State the number of different elements shown in this formula.
…………………………………………………………………………………………………………………….
(ii) State the total number of atoms shown in this formula.
…………………………………………………………………………………………………………………….
(c) Magnesium is a metal.
(i) Describe two physical properties of metals.
1 …………………………………………………………………………………………………………………
2 ………………………………………………………………………………………………………………..
(ii) Table 11.1 shows the percentage composition of a magnesium alloy.
Calculate the mass of magnesium contained in 50kg of the alloy.
Show your working.
mass of magnesium = …………………………….. kg
▶️Answer/Explanation
Ans: 11(a)(i) (sulfuric acid) + magnesium → hydrogen + magnesium sulfate
magnesium and hydrogen ;
magnesium sulfate ;
11(a)(ii) gets hot / temperature increases ;
fizzing / bubbles / effervescence ;
11(a)(iii)
2 hydrogen atoms ;
1 shared pair of electrons only ;
11(b)(i) 3 ;
11(b)(ii) 7 ;
11(c)(i) any two from:
good conductor of electricity ;
good conductor of heat ;
high melting / boiling point ;
malleable ;
11(c)(ii) • 96 (%) seen ;
• 48 (kg) ;
Question
(a) Sodium forms a basic oxide. Carbon forms acidic oxides.
State why they are different.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(b) Carbon is a solid and carbon dioxide is a gas.
Describe the differences between a solid and a gas using ideas about particle separation and particle motion.
particle separation ……………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………………
particle motion …………………………………………………………………………………………………………..
…………………………………………………………………………………………………………………………………
(c) Diamond is one form of carbon.
Fig. 11.1 shows the arrangement of carbon atoms in diamond.
two words from the list to describe the structure and bonding in diamond.
simple giant metallic ionic covalent polymer
(d) (i) Sodium metal reacts with chlorine gas to make sodium chloride.
Balance the symbol equation for this reaction.
……..Na + Cl$_{2}$ → ……..NaCl
(ii) During the reaction sodium atoms form sodium ions, Na$^{+}$, and chlorine atoms form
chloride ions, Cl$^{-}$.
Fig. 11.2 shows the electronic structure of a sodium ion and a chloride ion.
Write down the electronic structure of a sodium atom and a chlorine atom.
sodium atom ………………………………………………………………………………………………………
chlorine atom ……………………………………………………………………………………………………..
(iii) Sodium and lithium are both in Group I of the Periodic Table.
Sodium reacts violently with water.
Describe the reaction of lithium with water.
Describe the trend in the reactivity of Group I elements as shown by sodium and lithium.
reaction ……………………………………………………………………………………………………………..
………………………………………………………………………………………………………………………….
explanation …………………………………………………………………………………………………………
………………………………………………………………………………………………………………………….
▶️Answer/Explanation
Ans: 11(a) non-metals form acidic oxides and metals form basic oxides ;
11(b) (solid) closer together / (gas) further apart) ;
(solid) vibrating about a fixed point / (gas) free to move / faster ;
11(c) giant ;
covalent ;
11(d)(i) 2 Na and 2 NaCl ;
11(d)(ii) 2, 8, 1 ;
2, 8, 7 ;
11(d)(iii) lithium reacts less rapidly / quickly ;
(metal) reactivity increases down group ;
Question
(a) Substances are separated from mixtures of substances using different methods.
Draw one straight line from each substance to the correct method of separating it from the mixture.
One line has been drawn for you.
(b) One reason for separating mixtures is to purify substances.
Explain the importance of purity in the manufacture of substances used in food additives.
(c) The element lead is obtained from the compound lead(II) bromide by electrolysis.
(i) Describe the difference between an element and a compound.
(ii) Complete the sentences to describe the electrolysis of lead(II) bromide.
Electrolysis is the breakdown of molten lead(II) bromide by the passage of ………………………………………… .
The gas released at the positive electrode is ………………………………………… and ………………………………………… is formed at the negative electrode.
The negative electrode is called the ………………………………………… .
(d) A student reacts dilute hydrochloric acid with four metals.
The student’s observations are shown in Table 5.1.
Place the four metals in order of their reactivity from the most reactive to the least reactive.
▶️Answer/Explanation
Ans : 5(a) 
5(b) to avoid poisoning ;
5(c)(i) element contains only one type of atom /
compound consists of (atoms of) two or more elements (chemically combined) ;
5(c)(ii) electricity ;
bromine and lead ;
cathode ;
5(d) calcium
magnesium
lead
copper
;;
Question
(a) The list gives the names of seven elements.
aluminium carbon copper chlorine
helium phosphorus sulfur
State which of the elements in the list:
(i) forms diamond and graphite ……………………………………………………………………………
(ii) is a halogen …………………………………………………………………………………………………..
(iii) is electroplated onto another metal …………………………………………………………………..
(iv) is extracted from bauxite …………………………………………………………………………………
(v) is used in the manufacture of sulfuric acid …………………………………………………………
(vi) is used to sterilise drinking water ……………………………………………………………………..
(b) The formula of phosphorus oxide is P4O10.
State the number of atoms of phosphorus and of oxygen contained in one molecule of phosphorus oxide.
phosphorus ………………………………………………………………..
oxygen ………………………………………………………………………..
(c) Explain why phosphorus oxide makes an acidic solution when it dissolves in water.
(d) Phosphorus is contained in fertilisers.
State the two other elements commonly found in fertilisers.
1 …………………………………………………………………………
2 …………………………………………………………………………
▶️Answer/Explanation
Ans : 2(a)(i) carbon ;
2(a)(ii) chlorine ;
2(a)(iii) copper ;
2(a)(iv) aluminium ;
2(a)(v) sulfur ;
2(a)(vi) chlorine ;
2(b) phosphorus 4 oxygen 10 ;
2(c) non-metal oxides are acidic or non-metal oxides form acidic solutions ;
2(d) nitrogen ;
potassium ;
Question
(a) State the name given to mixtures made from a metal with other elements.
(b) Iron is an element in Period 4 of the Periodic Table.
State the name of the collection of metals in Period 4 that contains iron.
(c) Describe the test used to identify iron(II) ions and give the observation for a positive result.
test ………………………………………………………………….
observation …………………………………………………….
(d) State the two substances that react with iron to make rust.
1 …………………………………………………………………………
2 ……………………………………………………………………….
(e) An isotope of iron has a proton number of 26 and a nucleon number of 58.
(i) Deduce the number of neutrons and the number of electrons in this isotope of iron.
neutrons = ………………………………………………………
electrons = ………………………………………………………
(ii) State the meaning of the term isotope.
(f) A teacher reacts dilute hydrochloric acid with four metals.
The observations are shown in Table 11.1.
Place the four metals in order of their reactivity from the most reactive to the least reactive.
most reactive ……………………………………………………………………..
least reactive ………………………………………………………………………
▶️Answer/Explanation
Ans : 11(a) alloy ;
11(b) transition elements / metals ;
11(c) aqueous sodium hydroxide ;
green precipitate ;
11(d) oxygen ;
water ;
11(e)(i) neutrons = 32 ;
electrons = 26 ;
11(e)(ii) atoms of the same element that have different numbers of neutrons ;
11(f) lithium calcium iron silver lithium and / or silver correct ;
all else correct ;
Question
(a) An isotope of magnesium has a proton number (atomic number) of 12 and a nucleon number (mass number) of 26.
Complete Table 5.1 to show the numbers of neutrons and electrons in an atom of this isotope.
(b) Fig. 5.1 shows part of the reactivity series of metals.
Magnesium reacts slowly with cold water.
Use the reactivity series to predict the result when calcium reacts with cold water.
Explain your answer.
prediction ………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………
explanation ……………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………
(c) Magnesium reacts with carbon dioxide. Magnesium oxide and carbon are made.
(i) Write the word equation for this reaction.
(ii) The reaction between magnesium and carbon dioxide is exothermic.
State what is meant by the term exothermic.
……………………………………………………………………………………………………………………
……………………………………………………………………………………………………………………
(d) Platinum is a transition metal. Magnesium is not a transition metal.
State two properties of platinum that are not properties of magnesium.
1 …………………………………………………………………………………………………………………..
2 ………………………………………………………………………………………………………………….
(e) Table 5.2 shows the composition of an alloy of magnesium.
Complete the table with the % by mass of magnesium.
Calculate the mass of magnesium in 1.0kg of the alloy.
mass = ……………………………………………. kg
▶️Answer/Explanation
Ans: 5(a)
5(b) calcium reacts quickly/quicker ;
calcium is higher in reactivity series than magnesium ;
5(c)(i) magnesium + carbon dioxide → magnesium oxide + carbon ;
5(c)(ii) releases (thermal) energy ;
5(d) any two from:
forms coloured compounds ;
acts as catalyst ;
variable valency ;
5(e) 91.5 (%) ;
0.915 (kg) ;
Question
(a) Iron is an element in Period 4 of the Periodic Table.
- Name the collection of metals in Period 4 that contains iron.
- An atom of iron has a proton number of 26 and a nucleon number of 56. State the number of electrons in this atom.
Number of electrons - Iron is obtained from iron oxide by reaction with carbon. The word equation for the reaction is shown.
iron oxide + carbon → iron + carbon dioxide
Name the substance that is reduced in this reaction. Explain your answer.
Substance reduced
Explanation
▶️Answer/Explanation
Answer:
1. Transition metals
2. 26
3. Iron oxide
Explanation: Iron oxide loses oxygen, which is reduction.
Explanation:
– Iron is part of the transition metals in Period 4 of the Periodic Table.
– The number of electrons in an atom is equal to the proton number, which is 26 for iron.
– In the reaction, iron oxide (Fe₂O₃) loses oxygen to form iron (Fe), which is a reduction process.
(b) Steel is an alloy of iron.
- State what is meant by an alloy.
- State why steel is used rather than pure iron for making cars.
- Table 5.1 shows the percentage composition of an alloy.
Element Percentage Copper 33 Iron …… Nickel 60 Calculate the percentage of iron in the alloy.
Percentage of iron = …… %
▶️Answer/Explanation
Answer:
1. An alloy is a mixture of a metal with one or more other elements.
2. Steel is stronger and more resistant to corrosion than pure iron.
3. 7%
Explanation:
– An alloy is a mixture of metals or a metal with another element to improve its properties.
– Steel is preferred over pure iron because it is stronger and less prone to rusting.
– The percentage of iron in the alloy is calculated as follows:
Total percentage = 100%
Percentage of iron = 100% – (33% + 60%) = 7%.
(c) A student investigates the rusting of iron nails.
Fig. 5.1 shows the student’s experiments.
Table 5.2 shows the student’s observations after one week. Complete Table 5.2 to explain the student’s observations.
| Test-tube | Rusts/Does not rust | Explanation |
|---|---|---|
| X | Does not rust | …… |
| Y | Rusts | …… |
| Z | Does not rust | …… |
▶️Answer/Explanation
Answer:
| Test-tube | Rusts/Does not rust | Explanation |
|---|---|---|
| X | Does not rust | No water present |
| Y | Rusts | Oxygen (air) and water present |
| Z | Does not rust | No air and water can reach the nail |
Explanation:
– In test-tube X, there is no water, so rusting cannot occur.
– In test-tube Y, both oxygen and water are present, which are necessary for rusting.
– In test-tube Z, the nail is painted, preventing air and water from reaching it, so rusting does not occur.