No questions found
Which two processes are required to change ice into steam?
597
505
553
Which row describes how the volume of a gas changes when the temperature increases, or when the pressure increases? [Table_1]
501
536
592
Four substances in a mixture are listed. • calcium nitrate • iron(II) sulfate • oxygen • water Which statement describes the mixture?
598
568
590
An ion is represented by the symbol $^{18}_{8}\text{O}^{2-}$.
Which statements about this ion are correct?
1. The ion contains 8 electrons.
2. The ion contains 10 neutrons.
3. The ion contains 8 protons.
536
549
578
What is the meaning of the term nucleon number?
505
595
600
Which row describes the electrical conductivity of covalent and ionic compounds when solid and when molten? [Table_1]
562
571
507
Which statement about the bonding in sodium chloride is correct?
536
514
555
The diagram shows the arrangement of carbon atoms in a giant covalent structure. Which row identifies the substance and describes a use of this substance?
531
528
539
Which statement is the correct definition for molecular formula?
581
538
507
A compound, T, has the formula \( \text{CH}_3\text{Cl} \). Three statements about this compound are listed.
1. A molecule of the compound contains five atoms.
2. A molecule of the compound contains five different elements.
3. The relative molecular mass of the compound is 50.5.
Which statements are correct?
591
537
505
Iron water taps are often electroplated with a layer of chromium. Which statements explain why iron water taps are electroplated?
1. It improves the appearance of the taps.
2. It increases the strength of the taps.
3. It prevents the corrosion of the taps.
4. It improves the electrical conductivity of the taps.
595
567
596
Molten caesium bromide is electrolysed using inert electrodes. Which row identifies the product at each electrode? [Table_1]
509
514
564
Which equation represents the overall reaction in a hydrogen–oxygen fuel cell?
540
518
520
Which statements about endothermic reactions are correct?
1. The energy of the products is greater than the energy of the reactants.
2. The energy of the reactants is greater than the energy of the products.
3. The temperature of the surroundings increases during the reaction.
4. The temperature of the surroundings decreases during the reaction.
574
550
524
Which process is a physical change?
562
531
547
Magnesium reacts with dilute hydrochloric acid, HCl, to produce hydrogen gas. Which row identifies the reaction conditions that give the fastest rate of reaction?
[Table_1]
530
570
576
Which reaction produces a white-coloured substance?
540
552
551
In a blast furnace, iron is extracted when iron(III) oxide reacts with carbon monoxide. The equation is shown. $$\mathrm{Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2}$$ Which substance is oxidised and which is reduced in this reaction? [Table_1]
532
515
556
Which row shows the colours of litmus and methyl orange with solutions of acids or bases? [Table_1]
570
599
531
Aqueous sodium hydroxide is reacted with excess dilute hydrochloric acid. Which ion causes the resulting mixture to be acidic?
525
529
583
Universal indicator is added to an aqueous solution of oxide X. The indicator changes colour from green to red. What is X?
527
560
519
Which rows identify two aqueous salts which react together to produce a precipitate?
[Table_1]
524
596
593
Which statements about elements in the Periodic Table are correct?
1. Elements in the same group have the same number of electrons in their outer shell.
2. Elements in the same period have the same number of occupied electron shells.
3. The elements are arranged in order of their atomic mass.
4. Every period contains eight elements.
574
597
557
Four mixtures each contain a halogen and an aqueous sodium halide. Which row describes what happens in the mixtures shown? [Table_1]
536
593
522
Which row describes a transition element? [Table_1]
562
555
573
Which statement about the use of metals is correct?
518
554
562
Which statements explain why stainless steel is used in cutlery?
1. It is resistant to rusting.
2. It is a hard material.
3. It is a pure metal.
552
503
543
Four different metals are separately mixed with an equal volume of dilute hydrochloric acid. The table shows the rate of effervescence for each metal. [Table_1] What is the order of reactivity of the four metals starting with the most reactive?
533
569
502
Which statement about the rusting of iron is correct?
562
578
549
Water is extracted from a river for use in a domestic water supply. Some treatments for domestic water are listed. \begin{itemize} \item chlorination \item sedimentation and filtration \item treatment with carbon \end{itemize} Which statement about these treatments is correct?
509
523
563
A farmer knows his soil needs phosphorus and potassium.
He has a choice of four fertilisers.
1. $\text{NH}_4\text{NO}_3$
2. $(\text{NH}_4)_3\text{PO}_4$
3. $\text{KNO}_3$
4. $(\text{NH}_2)_2\text{CO}$
Which fertilisers should he use?
600
556
570
Which strategies are useful in reducing the production of acid rain? 1. planting trees 2. using catalytic converters in motor vehicles 3. reducing livestock farming 4. using low-sulfur fuels
523
571
500
The structures of four organic compounds, \( W, X, Y \) and \( Z \), are shown below: Which compounds are members of the same homologous series?
500
514
538
Which molecular formula represents an alkene?
515
517
505
Which row identifies the petroleum fractions used to reduce the friction between metal parts in engines and as a fuel in cars? [Table_1]
513
599
520
Four fuels are listed.
1. ethanol
2. coal
3. hydrogen
4. natural gas
Which fuels are fossil fuels?
589
580
595
Aqueous bromine is added to two test-tubes.
Excess hexene is added to one test-tube.
Excess hexane is added to the second test-tube.
Which row describes the observation in each test-tube?
590
564
537
The structure of a compound, G, is shown. G is in the same homologous series as ethanoic acid. Which row describes an aqueous solution of G?
536
550
553
When zinc reacts with dilute sulfuric acid, hydrogen gas is produced.
Which apparatus is needed to investigate the effect of temperature on the rate of this reaction?
1. thermometer
2. stop-watch
3. volumetric pipette
4. gas syringe
576
580
592
Two tests are carried out on substance Z.
test 1: A flame test produces a red flame.
test 2: Z is dissolved in water and dilute nitric acid is added, followed by aqueous silver nitrate. A yellow precipitate is produced.
What is substance Z?
591
573
555
