No questions found
Which two gases will diffuse at the same rate, at the same temperature?
568
535
533
A student measures the time taken for 2.0 g of magnesium to dissolve in 50 cm^3 of dilute sulfuric acid. Which apparatus is essential to complete the experiment?
543
518
567
A chromatogram of a single substance T is shown.
Which measurements are used to find the $R_f$ value of T?
599
521
533
X and Y are two different elements.
X and Y have the same number of nucleons.
Which statement about X and Y is correct?
541
527
506
The diagrams show the structures of three macromolecules P, Q and R.
[Image_1: Shows structure diagrams of P, Q, R]
What are P, Q and R?
[Table_1: Options for P, Q, R]
577
573
521
Which dot-and-cross diagram shows the arrangement of outer shell electrons in a molecule of hydrogen chloride?
558
548
515
The equation for the reaction between barium chloride and dilute sulfuric acid is shown.
\( \text{BaCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + 2\text{HCl} \)
Which row shows the state symbols for this equation?
[Table_1]
557
565
541
Methane and steam react in the presence of a catalyst.
$$\text{CH}_4(g) + \text{H}_2\text{O}(g) \rightarrow \text{CO}(g) + 3\text{H}_2(g)$$
0.5 mol of methane reacts completely with 0.5 mol of steam.
What is the volume of carbon monoxide and hydrogen produced, measured at room temperature and pressure?
[Table_1]
532
533
502
A compound of element X has the formula X$_2$O and a relative formula mass of 144.
What is element X?
588
525
534
The diagram shows the electrolysis of concentrated hydrochloric acid and concentrated aqueous sodium chloride using carbon electrodes.
At which electrodes is hydrogen produced?
565
578
511
The diagram shows the electrolysis of aqueous copper(II) sulfate using inert electrodes.
Which arrow shows the movement of electrons in the circuit?
527
564
557
Which row identifies a chemical change and a physical change?
[Table_1]
543
502
520
Which statements explain why increasing the concentration of a reactant increases the rate of reaction?
1. It increases the collision rate of particles.
2. It lowers the activation energy.
3. A greater proportion of the colliding molecules have the required activation energy.
4. There are more particles per unit volume.
577
549
581
When the colourless gas $N_2O_4$ is heated, it forms the brown gas $NO_2$.
When the reaction mixture is cooled, the brown colour fades and turns back to colourless.
Which type of reaction is described by these observations?
517
567
583
Water is added to anhydrous copper(II) sulfate. What happens during the reaction?
504
552
587
Which arrow on the energy level diagram shows the overall energy change for an endothermic reaction?
575
516
594
When a hydrogen–oxygen fuel cell is in operation, a different reaction happens at each electrode.
at the hydrogen electrode $H_2 \rightarrow 2H^+ + 2e^-$
at the oxygen electrode $O_2 + 2H_2O + 4e^- \rightarrow 4OH^-$.
The electrons that are lost at the hydrogen electrode travel through the external circuit to the oxygen electrode, where they are gained by the oxygen and water.
A hydrogen–oxygen fuel cell is operated for a period of time and four moles of oxygen molecules are consumed.
Which mass of hydrogen is consumed?
500
515
582
The oxides of two elements, X and Y, are separately dissolved in water and the pH of each solution tested.
[Table_1]
Which information about X and Y is correct?
593
519
597
An acid is neutralised by adding an excess of an insoluble solid base. A soluble salt is formed. How is the pure salt obtained from the reaction mixture?
559
511
506
Substance J takes part in a redox reaction. In the reaction, J gains electrons. Which statement is correct?
551
549
599
Elements in Group IV of the Periodic Table are shown.
carbon
silicon
germanium
tin
lead
What does not occur in Group IV as it is descended?
516
500
569
Which statement about acids is correct?
524
583
567
Which elements have both a high melting point and variable oxidation states?
573
560
577
Lithium, sodium and potassium are elements in Group I of the Periodic Table.
Chlorine, bromine and iodine are elements in Group VII of the Periodic Table.
Which row identifies the least dense of these elements in each group?
[Table_1]
545
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501
The reactions of metals P, Q, R, and S are shown.
[Table_1]
What is the order of reactivity of the metals?
550
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524
The number of protons and the number of neutrons in the atoms of elements X, Y and Z are shown.
[Table_1]
Which statement about the elements is correct?
509
531
510
Which diagram represents the arrangement of atoms in an alloy?
509
531
553
Three metal compounds, J, K and L, are heated using a Bunsen burner.
The results are shown.
J colourless gas produced, which relights a glowing splint
K colourless gas produced, which turns limewater milky
L no reaction
Which row identifies J, K and L?
[Table_1]
570
533
560
Processes involved in the extraction of zinc are listed.
1 Heat zinc oxide with carbon.
2 Condense zinc vapour.
3 Vaporise the zinc.
4 Roast zinc ore in air.
In which order are the processes carried out?
598
504
526
Which process uses sacrificial protection to prevent steel from rusting?
572
559
571
Fertilisers are used to provide three of the elements needed for plant growth. Which two compounds would give a fertiliser containing all three of these elements?
503
571
523
Which processes produce carbon dioxide?
1 respiration
2 photosynthesis
3 fermentation
4 combustion of hydrogen
598
511
567
Which reaction in the Contact process requires the use of a catalyst?
530
568
556
What are the products when limestone (calcium carbonate) is heated strongly?
561
535
515
The structure of ester W is shown.
Which row gives the names of ester W and the carboxylic acid and alcohol from which it is made?
553
536
507
Ethene reacts with substance X to form ethanol.
What is X?
594
595
585
Alkenes can be produced by cracking large hydrocarbon molecules to form smaller hydrocarbon molecules.
Which equations represent possible reactions when tetradecane, $C_{14}H_{30}$, is cracked?
1 $\quad C_{14}H_{30} \rightarrow C_{2}H_{6} + C_{3}H_{6} + C_{4}H_{8} + C_{5}H_{10}$
2 $\quad C_{14}H_{30} \rightarrow H_{2} + C_{2}H_{4} + C_{3}H_{6} + C_{4}H_{8} + C_{5}H_{10}$
3 $\quad C_{14}H_{30} \rightarrow C_{2}H_{6} + 4C_{3}H_{6}$
4 $\quad C_{14}H_{30} \rightarrow C_{2}H_{6} + C_{3}H_{8} + C_{9}H_{18}$
581
541
523
The structures of some hydrocarbons are shown.
Which statement about the hydrocarbons is correct?
557
596
506
Ethane reacts with chlorine in the presence of ultraviolet light.
Which substances are produced in the reaction?
597
504
560
Which polymer structure has the same linkages as Terylene?
582
596
568
