No questions found
Small crystals of purple $\text{KMnO}_4$ $(M_r = 158)$ and orange $\text{K}_2\text{Cr}_2\text{O}_7$ $(M_r = 294)$ were placed at the centres of separate petri dishes filled with agar jelly. They were left to stand under the same physical conditions. After some time, the colour of each substance had spread out as shown.
The lengths of the arrows indicate the relative distances travelled by particles of each substance.
Which statement is correct?
535
554
545
Pure water has a boiling point of 100 °C and a freezing point of 0 °C.
What is the boiling point and freezing point of a sample of aqueous sodium chloride? [Table_1]
590
575
565
A chromatogram obtained from the chromatography of four substances is shown.
Which substance has an $R_f$ value of 0.6?
523
507
507
Sodium reacts with chlorine to form sodium chloride.
Which statements describe what happens to the sodium atoms in this reaction?
1. Sodium atoms form positive ions.
2. Sodium atoms form negative ions.
3. Sodium atoms gain electrons.
4. Sodium atoms lose electrons.
534
511
533
Diamond is extremely hard and does not conduct electricity.
Which statement explains these properties?
524
598
502
Which statement about metals is not correct?
578
519
505
Aluminium reacts with fluorine.
$xAl(s) + yF_2(g) \rightarrow zAlF_3(s)$
Which values of $x$, $y$ and $z$ balance the equation?
[Table_1]
519
552
511
Carbon monoxide burns in oxygen to produce carbon dioxide.
$$2\text{CO}(g) + \text{O}_2(g) \rightarrow 2\text{CO}_2(g)$$
Which mass of carbon dioxide is produced from 14 g of carbon monoxide?
576
587
583
Which statement about electrolysis is correct?
585
543
593
The reactivity series for a number of different metals is shown.
[Image_1: Reactivity series and diagram]
The diagram shows different metal strips dipped into an electrolyte.
Which pair of metals produces the highest voltage?
539
519
549
Some properties of four fuels are shown in the table.
Which fuel is a gas at room temperature and makes two products when it burns in a plentiful supply of air?
[Table_1]
596
545
532
Which statements about exothermic and endothermic reactions are correct?
1. During an exothermic reaction, heat is given out.
2. The temperature of an endothermic reaction goes up because heat is taken in.
3. Burning methane in the air is an exothermic reaction.
519
594
575
Chlorine reacts with ethane to produce chloroethane and hydrogen chloride.
The reaction is exothermic.
The bond energies are shown in the table.
[Table_1]
What is the energy change for the reaction?
577
562
581
When sulfur is heated it undergoes a ......1...... change as it melts. Further heating causes the sulfur to undergo a ......2...... change and form sulfur dioxide. Which words complete gaps 1 and 2? [Table_1]
519
510
569
A student was investigating the reaction between marble chips and dilute hydrochloric acid.
Which changes slow down the rate of reaction?
555
526
528
Nitrogen, hydrogen and ammonia gases are placed inside a container. The container is then sealed. After some time, an equilibrium forms.
$\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g)$
Which statement describes the equilibrium in this container?
518
536
567
An example of a redox reaction is shown.
$\text{Zn} + \text{Cu}^{2+} \rightarrow \text{Zn}^{2+} + \text{Cu}$
Which statement about the reaction is correct?
516
594
598
Zinc oxide is amphoteric.
Which row describes the reactions of zinc oxide?
[Table_1]
reaction with hydrochloric acid
reaction with aqueous sodium hydroxide
A. ✓ ✓
B. ✓ ✗
C. ✗ ✓
D. ✗ ✗
key
✓ = reaction occurs
✗ = reaction does not occur
572
573
584
Which row shows how the hydrogen ion concentration and pH of ethanoic acid compare to those of hydrochloric acid of the same concentration?
[Table_1]
566
521
524
A pure sample of the insoluble salt barium carbonate can be made using the method given.
step 1 Dissolve barium chloride in water.
step 2 Separately dissolve sodium carbonate in water.
step 3 Mix the two solutions together.
step 4 Filter the mixture.
step 5
step 6 Dry the residue between two sheets of filter paper.
Which instruction is missing from step 5?
505
532
535
Substance X reacts with warm dilute hydrochloric acid to produce a gas which decolourises acidified aqueous potassium manganate(VII).
Substance X gives a yellow flame in a flame test. What is X?
594
568
567
Which element is less reactive than the other members of its group in the Periodic Table?
518
564
511
The elements in Group IV of the Periodic Table are shown.
carbon
silicon
germanium
tin
lead
flerovium
What does not occur in Group IV as it is descended?
551
521
552
Why are weather balloons sometimes filled with helium rather than hydrogen?
532
547
513
Metal X is added to a colourless aqueous solution of the sulfate of metal Y.
A coloured solution is formed and metal Y is deposited at the bottom of the beaker.
Which row describes elements X and Y and their relative reactivity?
[Table_1]
515
565
589
Element E:
• forms an alloy
• has a basic oxide
• is below hydrogen in the reactivity series.
What is E?
584
547
500
Zinc metal is extracted from its ore zinc blende in a similar method to that used to extract iron from hematite. In which way is zinc extraction different from iron extraction?
594
527
533
Stainless steel is an alloy of iron and other metals. It is strong and does not rust but it costs much more than normal steel. What is not made from stainless steel?
519
549
592
The diagram shows some uses of water in the home.
For which uses is it important for the water to have been treated?
570
543
523
Oxides of nitrogen are found in polluted air. Which statement about oxides of nitrogen is correct?
510
504
557
Photosynthesis and respiration are important natural processes. Which statement is correct?
598
550
534
Which row gives the conditions for the Haber process?
[Table 1: temperature/°C, pressure/atm, catalyst]
500
524
561
Which statement about sulfuric acid is correct?
556
590
506
Which statement is not correct?
502
546
564
Which fraction of petroleum is not matched to its correct use?
[Table_1]
502
579
508
The diagram shows the structures of two organic molecules.
Which statement about these molecules is not correct?
600
588
503
The diagram shows part of the molecule of a polymer.
Which diagram shows the monomer from which this polymer could be manufactured?
534
541
587
Ethanol is manufactured by fermentation or by the catalytic addition of steam to ethene. Which statement is correct?
586
529
592
The structure of an ester is shown.
Which row is correct?
[Table_1]
525
547
589
Keratin is a protein that is found in human hair.
Keratin is chemically broken down to produce amino acids.
What is the name of this chemical process?
592
509
564
