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1. Iron ore contains iron(III) oxide, $Fe_2O_3$. A blast furnace is used to extract iron from $Fe_2O_3$. Equations for some of the reactions in the blast furnace are shown:
Equation 1: $C + O_2 \rightarrow CO_2$
Equation 2: $CaCO_3 \rightarrow CaO + CO_2$
Equation 3: $CaO + SiO_2 \rightarrow CaSiO_3$
(a) Equation 1 shows the combustion of carbon in the blast furnace.
(i) Name the substance which provides the carbon for this reaction. [1]
(ii) State the purpose of the combustion of carbon in the blast furnace. [1]
(b) Iron(III) oxide, $Fe_2O_3$, in iron ore is converted to iron when it reacts with carbon monoxide, CO, in the blast furnace.
(i) Calculate the percentage by mass of iron in iron(III) oxide, $Fe_2O_3$. [2]
(ii) State the name of the iron ore which consists mainly of iron(III) oxide. [1]
(iii) Describe how carbon monoxide is formed in the blast furnace. [1]
(iv) Write the symbol equation to show the reaction that occurs when iron(III) oxide is converted to iron in the blast furnace. [2]
(v) Name the chemical process which happens to iron when iron(III) oxide is converted to iron in the blast furnace. [1]
(c) State the type of reaction shown by equation 2. [1]
(d) (i) Explain why the reaction in equation 3 can be described as an acid–base reaction. [2]
(ii) State:
- the chemical name of $SiO_2$ [1]
- the common name given to $CaSiO_3$ when it is formed in the blast furnace. [1]
(e) Aluminium cannot be extracted from its ore using a blast furnace.
(i) State why aluminium is not extracted from its ore using a blast furnace. [1]
(ii) Name the process used to extract aluminium from its ore. [1]
(f) Both iron(III) oxide and aluminium oxide contain metal ions with a 3+ charge.
(i) Write the electronic configuration of an $Al^{3+}$ ion. [1]
(ii) Deduce the number of protons and electrons in an $Fe^{3+}$ ion.
protons ____ electrons ____ [2]
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2. The elements in Group VII of the Periodic Table are known as the halogens. Halogens can form halide ions.
(a) Identify the halogen with the lowest density at r.t.p. (room temperature and pressure). [1]
(b) State the appearance of bromine at r.t.p. [1]
(c) Use the Periodic Table to:
- give the symbol of the halogen with the highest atomic number
- deduce the number of occupied electron shells in an atom of this element. [2]
(d) Bromine molecules have covalent bonding.
(i) State what is meant by the term covalent bond. [2]
(ii) Name one halide ion which bromine molecules can displace. [1]
(iii) Explain why bromine can displace the halide ion in (d)(ii). [1]
(e) Name a halide compound which can be used to detect the presence of water. [2]
(f) Calcium chloride is an ionic compound. Complete the dot-and-cross diagram for the ions in calcium chloride. Give the charges on each of the ions. [3]
(g) Aqueous lead(II) ions are added to aqueous chloride ions. A white precipitate of insoluble lead(II) chloride, $PbCl_2$, is formed.
(i) Name a lead(II) compound which can be used in this reaction. [1]
(ii) Write the ionic equation for this reaction. Include state symbols. [3]
(iii) Name one other insoluble chloride. [1]
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3. This question is about acids, bases, and alkalis. Table 3.1 shows the pH values of some substances.
Table 3.1
Substance pH
NaOH(aq) 14
Ca(OH)2(aq) 10
H2O(l) 7
CH3COOH(aq) 4
HNO3(aq) 1
(a) Define the term base. [1]
(b) State what is meant by the term alkali. [1]
(c) Thymolphthalein is an indicator.
State the colour of thymolphthalein in:
- NaOH(aq) ____ [1]
- CH3COOH(aq) ____ [1]
(d) (i) Use the information in Table 3.1 to identify the substance with the highest concentration of $H^+$(aq) ions.
Explain your answer. [2]
(ii) Name an indicator which can be used to identify the substance with the highest concentration of $H^+$(aq) ions. [1]
(e) Complete the equation to show the dissociation of ethanoic acid, $CH_3COOH$, in aqueous solution.
$CH_3COOH(aq) \rightarrow $ ____ [3]
(f) Write the ionic equation which represents a neutralisation reaction between any acid and any alkali. [1]
(g) Dilute nitric acid, $HNO_3(aq)$, reacts with aqueous calcium hydroxide, $Ca(OH)_2(aq)$, as shown.
$2HNO_3(aq) + Ca(OH)_2(aq) \rightarrow Ca(NO_3)_2(aq) + 2H_2O(l)$
20.0cm³ of 0.0150mol/dm³ $Ca(OH)_2(aq)$ reacts with 25.0cm³ of $HNO_3(aq)$.
Calculate the concentration of $HNO_3(aq)$ in g/dm³. Use the following steps:
- Calculate the number of moles of $Ca(OH)_2(aq)$ used. ____ mol
- Determine the number of moles of $HNO_3(aq)$ which react with the $Ca(OH)_2(aq)$. ____ mol
- Calculate the concentration of $HNO_3(aq)$ in mol/dm³. ____ mol/dm³
- Calculate the concentration of $HNO_3(aq)$ in g/dm³. ____ g/dm³ [5]
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4. The equation for the reaction between methanoic acid and ethanol in the presence of a catalyst can be represented as shown.
$HCOOH + CH_3CH_2OH \rightarrow X + H_2O \Delta H = -29.5\text{kJ/mol}$
$X$ represents the ester formed.
(a) (i) In the equation, methanoic acid is represented by the formula $HCOOH$. Name this type of formula. [1]
(ii) Write the empirical formula of methanoic acid. [1]
(b) Name and draw the displayed formula of ester $X$.
name ____
displayed formula ____ [3]
(c) The reaction is reversible and reaches an equilibrium within a closed system.
(i) State what is meant by the term closed system. [1]
(ii) State two characteristics of an equilibrium.
1 ____
2 ____ [2]
(iii) Complete Table 4.1 to show the effect, if any, on the concentration of $X$ at equilibrium for each change of condition.
Table 4.1
Change of condition
- Temperature is decreased
- Concentration of $HCOOH$ is decreased
- Concentrations of both $HCOOH$ and $CH_3CH_2OH$ are decreased
- The catalyst is removed [4]
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5. Butane and but-1-ene are colourless gases at room temperature and pressure.
(a) Suggest why but-1-ene diffuses quicker than butane. [1]
(b) Identify the products formed when butane undergoes complete combustion. [1]
(c) One molecule of butane reacts with one molecule of chlorine in the presence of ultraviolet light. During the reaction, one hydrogen atom in butane is replaced by one chlorine atom.
(i) Name the type of reaction which needs ultraviolet light. [1]
(ii) State the purpose of ultraviolet light during this reaction. [1]
(iii) Name the type of reaction which takes place when one atom of chlorine replaces one atom of hydrogen. [1]
(iv) Determine how many different structural isomers can form during this reaction. [1]
(d) When but-1-ene reacts with steam, two possible products form.
(i) Identify the type of catalyst which is used in this reaction. [1]
(ii) Name and draw the displayed formulae of the two possible products.
Product 1 name ____
Displayed formula ____
Product 2 name ____
Displayed formula ____ [4]
(e) But-1-ene undergoes polymerisation.
(i) State the type of polymerisation but-1-ene undergoes. [1]
(ii) Draw part of the polymer molecule to show three repeat units. [3]
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