No questions found
Which statement describes sublimation?
553
521
590
25 cm$^3$ of an alkali are added to 20 cm$^3$ of an acid. The temperature change is measured. Which apparatus is not needed in the experiment?
587
579
516
The painkiller paracetamol is synthesised from 4-aminophenol.
Chromatography was carried out on an impure sample of paracetamol. The results are shown (not drawn to scale).
The sample of paracetamol was contaminated with 4-aminophenol only.
What is the $R_f$ value of 4-aminophenol?
559
599
584
Which compound is silicon(IV) oxide?
[Table_1]
melting point (°C)
A: -73
B: 801
C: 1495
D: 1710
good electrical conductor when solid
A: no
B: no
C: yes
D: no
good electrical conductor when molten
A: no
B: yes
C: yes
D: no
587
540
564
Carbon has three naturally occurring isotopes, $^{12} ext{C}$, $^{13} ext{C}$ and $^{14} ext{C}$.
Which statement explains why the isotopes have the same chemical properties?
578
523
596
Which dot-and-cross diagram shows the outer shell electron arrangement in a molecule of carbon dioxide?
534
526
579
The equation represents the reaction between solid magnesium oxide and dilute hydrochloric acid to form magnesium chloride and water.
$$\text{MgO} + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2\text{O}$$
Which row shows the state symbols for hydrochloric acid, magnesium chloride and water?
[Table_1]
543
544
510
A compound contains 34.5% calcium, 24.1% silicon and 41.4% oxygen by mass.
What is its empirical formula?
570
599
517
Which statements about the electrolysis of concentrated copper(II) chloride are correct?
1. Electrons are transferred from the cathode to the copper(II) ions.
2. Electrons move round the external circuit from the cathode to the anode.
3. Chloride ions are attracted to the anode.
4. Hydroxide ions transfer electrons to the cathode.
506
552
594
Which metal combination produces the highest voltage reading in the cells shown?
529
591
539
Some bond energies are shown in the table.
[Table_1: bond energies]
Hydrogen reacts with oxygen. The reaction is exothermic.
$$2H_2(g) + O_2(g) \rightarrow 2H_2O(g)$$
What is the energy change for the reaction?
527
596
595
Which statement describes an exothermic reaction?
512
574
519
The mass of a beaker and its contents is plotted against time.
Which graph represents what happens when sodium carbonate reacts with an excess of dilute hydrochloric acid in an open beaker?
544
506
512
Silver chloride reacts when it is exposed to light. Which row shows what happens to the silver in this process?
[Table_1]
519
589
519
Which statement about the effect of concentration and temperature on the rate of a reaction is not correct?
534
584
589
The following reaction has reached equilibrium in a closed system.
$2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$
The forward reaction is exothermic.
Which row shows the effect of increasing the pressure on the equilibrium mixture?
[Table_1]
575
552
557
Some properties of four oxides are listed.
Oxide 1 reacts with both acids and alkalis to form salts.
Oxide 2 reacts with acids to form salts but does not react with alkalis.
Oxide 3 reacts with alkalis to form salts but does not react with acids.
Oxide 4 does not react with acids or alkalis.
Which row describes the oxides?
[Table_1]
556
580
510
What is not a typical characteristic of acids?
532
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514
Three solids, P, Q and R, all react with dilute sulfuric acid to produce zinc sulfate. P and R produce gases during the reaction. The gas produced when P reacts will not burn. The gas produced when R reacts will burn.
What are P, Q and R?
[Table_1]
501
514
535
Which ion forms a green precipitate with aqueous sodium hydroxide that dissolves in an excess of aqueous sodium hydroxide?
530
500
539
A period of the Periodic Table is shown.
[Table_1]
The letters are not their chemical symbols.
Which statement is correct?
537
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535
Some properties of element X are shown.
[Table_1]
In which part of the Periodic Table is X found?
581
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508
The table gives some properties of an element.
[Table_1]
Which other property would you expect this element to have?
539
527
527
Why is argon gas used to fill electric lamps?
517
528
540
Aluminium is obtained by the electrolysis of a mixture of aluminium oxide and cryolite.
Why is cryolite used?
578
542
552
Metal M is mixed with copper to produce brass. What is M?
563
566
564
Some metal nitrates and carbonates decompose when heated strongly.
Metal Q has a nitrate that decomposes to give a salt and a colourless gas only.
The carbonate of metal Q does not decompose when heated with a Bunsen burner.
What is metal Q?
511
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515
The flow chart shows stages in the treatment of river water to produce drinking water.
What occurs at stages X and Y?
519
563
526
A piece of zinc is attached to the hull of a steel boat. Steel is an alloy of iron. Which statement explains why the zinc prevents the iron from rusting?
532
500
565
The Haber process for making ammonia is carried out at a temperature of 450°C and a pressure of 200 atmospheres in the presence of a catalyst.
Which statement is not correct?
561
566
600
Which process does not produce carbon dioxide?
554
587
521
Which row shows the conditions used in the manufacture of sulfuric acid by the Contact process? [Table_1]
536
591
589
Some marble chips (calcium carbonate) are heated strongly and substances X and Y are formed.
Substance X is a white solid that reacts with water, giving out heat. Substance Y is a colourless gas.
What are substances X and Y?
574
521
564
The structure of compound R is shown.
What is R?
593
517
527
Fuel oil and naphtha are two fractions obtained from petroleum.
What are the major uses of these fractions?
[Table_1]
547
563
544
X, Y and Z are three hydrocarbons.
\( X \quad \text{CH}_2=\text{CH}_2 \quad Y \quad \text{CH}_3-\text{CH}=\text{CH}_2 \quad Z \quad \text{CH}_3-\text{CH}_2-\text{CH}=\text{CH}_2 \)
What do compounds X, Y and Z have in common?
1 They are all alkenes.
2 They are all part of the same homologous series.
3 They all have the same boiling point.
592
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593
The diagram shows a reaction sequence.
Which row names the processes X, Y and Z?
508
567
502
The structure of an ester is shown.
Which combination of carboxylic acid and alcohol produces this ester?
[Table_1]
596
596
508
The equation shows the formation of a polymer called Kevlar.
Which row describes Kevlar?
583
501
537
