No questions found
A mixture of ice and water is left to stand and the ice melts.
Which row describes what happens as the ice is melting?
[Table_1]
589
585
533
Which piece of apparatus is used to measure 25.0 cm$^3$ of aqueous sodium hydroxide?
528
563
529
Paper chromatography is used to determine the $R_f$ values for four different food colourings. Which food colouring has an $R_f$ value of 0.6?
566
528
539
The diagram shows the electronic structure of a particle with a nucleon number (mass number) of 40.
The table shows the suggestions that three students, 1, 2 and 3, made to identify the particle.
[Table_1]
Which students are correct?
524
542
585
The electronic structures of two atoms, P and Q, are shown.
P and Q combine together to form a compound.
What is the type of bonding in the compound and what is the formula of the compound?
[Table_1]
535
538
507
Which statement about the structure of a metal explains why metals are malleable?
508
579
546
The bonding, structure and melting point of sodium chloride and sulfur dichloride are shown.
[Table_1]
Why does sulfur dichloride have a lower melting point than sodium chloride?
565
505
512
Lead(II) nitrate, $\text{Pb(NO}_3)_2$, reacts with potassium iodide, KI, to form a yellow precipitate, PbI$_2$, and a soluble salt, KNO$_3$.
What is the equation for the reaction?
517
580
556
The Haber process is a reversible reaction.
$N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$
The reaction has a 30\% yield of ammonia.
Which volume of ammonia gas, $NH_3$, measured at room temperature and pressure, is obtained by reacting 0.75 moles of hydrogen with excess nitrogen?
502
529
572
Electrolytes can be broken down by electrolysis. Which rows are correct for each electrolyte?
[Table_1]
555
519
584
The electrolysis of aqueous copper(II) sulfate, using inert electrodes, is shown.
Which statement about a reaction at an electrode is correct?
559
569
580
Methane burns in excess oxygen.
The equation is shown.
$\text{CH}_4(g)\ +\ 2\text{O}_2(g)\ \rightarrow\ \text{CO}_2(g)\ +\ 2\text{H}_2\text{O}(g)$
Bond energies are shown.
[Table_1]
What is the energy change for the reaction?
533
503
580
Which statements about hydrogen fuel cells are correct?
1. Water is formed as the only waste product.
2. Both water and carbon dioxide are formed as waste products.
3. The overall reaction is $2H_2 + O_2 \rightarrow 2H_2O$.
4. The overall reaction is endothermic.
595
538
596
Which list contains only chemical changes?
525
541
576
The results of adding excess marble chips (calcium carbonate) to hydrochloric acid at 50°C and at 30°C are shown. Only the temperature is changed.
Which row describes the reacting particles at 30°C compared to those at 50°C?
570
592
500
Methane reacts with steam and an equilibrium is reached.
$$\text{CH}_4(g) + \text{H}_2\text{O}(g) \rightleftharpoons \text{CO}(g) + 3\text{H}_2(g)$$
The forward reaction is endothermic.
Which row shows how the amount of hydrogen at equilibrium changes when the pressure or temperature is changed as indicated?
[Table_1]
578
592
541
When aqueous iron(III) chloride is added to aqueous potassium iodide a chemical reaction occurs and iodine is formed.
Which statement is correct?
577
529
509
The graph shows how the pH of a solution changes as an acid is added to an alkali.
acid + alkali → salt + water
Which letter represents the area of the graph where both acid and salt are present?
530
531
543
The apparatus shown is used to prepare aqueous copper(II) sulfate.
What are X and Y?
591
511
500
Which process is not used in the preparation of an insoluble salt?
583
513
542
Which statement about Group I and Group VII elements is correct?
536
582
529
The properties of the element titanium, Ti, can be predicted from its position in the Periodic Table. Which row identifies the properties of titanium? [Table_1]
509
594
585
Which diagram shows a mixture of noble gases?
518
523
567
Which property is shown by all metals?
550
580
594
Many metal carbonates decompose when they are heated.
Which row describes what happens when potassium carbonate, calcium carbonate and copper(II) carbonate are heated using a Bunsen burner?
[Table_1]
500
507
522
Molten iron from the blast furnace contains impurities.
The process of turning the impure iron into steel involves blowing oxygen into the molten iron and adding calcium oxide.
What are the reasons for blowing in oxygen and adding calcium oxide?
[Table_1]
586
503
501
Four iron nails are added to four different metal sulfate solutions. In which solution does a displacement reaction occur?
594
526
540
Which statement about pure water is not correct?
544
597
561
Three processes in the carbon cycle are shown.
1. Methane reacts with oxygen producing carbon dioxide and water.
2. Carbon dioxide and water are absorbed and used by plants to make oxygen.
3. Oxygen is used by living things to release energy.
Which processes have taken place? [Table_1]
517
576
524
In the Haber process, nitrogen and hydrogen are reacted to make ammonia.
$\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g)$
The forward reaction is exothermic.
Which conditions produce the maximum yield of ammonia?
[Table_1]
530
566
526
Which process, used to prevent iron from rusting, involves sacrificial protection?
582
596
541
A student suggests three uses of calcium carbonate (limestone).
1. manufacture of cement
2. manufacture of iron
3. treating alkaline soils
Which suggestions are correct?
590
597
566
One of the reactions used in the manufacture of sulfuric acid is shown.
$2SO_2 + O_2 \rightleftharpoons 2SO_3$
Which catalyst is used to increase the rate of this reaction?
544
592
562
Ethanol is made on an industrial scale by the fermentation of sugars or by the reaction of ethene with steam in the presence of a suitable catalyst.
What is a disadvantage of making ethanol from ethene rather than by fermentation?
504
543
586
Which statement about compounds in the same homologous series is correct?
516
553
567
Increasing the number of atoms in one molecule of a hydrocarbon increases the amount of energy released when it burns.
What is the correct order?
[Table_1]
589
544
507
An organic compound, P, reacts with zinc to produce a gas, Q. What are P and Q?
[Table_1]
537
538
580
Alkanes undergo substitution reactions in the presence of UV light.
Which equation represents a substitution reaction of ethane?
547
582
515
Which substances are natural polymers?
1 proteins
2 carbohydrates
3 nylon
4 poly(ethene)
597
566
543
