SLST IX-X Physical Science Online Free Mock Test: Set 1

1. The hydrogen molecule contains a covalent bond. What holds the atoms together in this covalent molecule?

2.

Q2. The actual values of the masses of three sub-atomic particles are shown in the table:

Which nickel ion is predicted to have a mass of 1.038 × 10⁻²⁵ kg from these data?

3.

Which statement about 1 mol of a metal is always correct?

4. Which statement about this structure ice crystal is correct?

5.

The head of the first type of match, called a ‘lucifer’, contained a mixture of antimony(III) sulfide and potassium chlorate(V). When the match was ‘struck’, the following reaction took place:

Sb₂S₃(s) + 3KClO₃(s) → Sb₂O₃(s) + 3KCl(s) + 3SO₂(g)

Which element is reduced in the reaction?

6.

Use of the data booklet is relevant to this question.

The successive ionisation energies, in kJ mol⁻¹, of an element X are given:

870, 1800, 3000, 3600, 5800, 7000, 13200

What is X?

7.

Synthetic rubber is commonly produced from the monomer buta-1,3-diene.

What are the numbers of σ bonds and π bonds present in one molecule of buta-1,3-diene?

8.

Polymerisation of ethene gives poly(ethene).

How does the carbon-carbon bond in poly(ethene) compare with that in ethene?

9.

The elements phosphorus, sulfur and chlorine all exhibit covalent bonding. Their melting points are listed:

• phosphorus: 44°C
• sulfur: 115°C
• chlorine: −101°C

What accounts for these differences in melting points?

10. Which set of bond angles in pyruvic acid [ CH₃–CO–CO₂H ] would be predicted by Valence Shell Electron Pair Repulsion theory?

11.

The gases butane, 2-methylpropane and propane are kept in a sealed container at atmospheric pressure and room temperature.

Which row represents the order in which these gases will liquefy as the pressure in the container is gradually increased?

12.

Ammonia gas reacts with gaseous hydrogen chloride to form a white smoke of ammonium chloride.

Which statements correctly describe the behaviour of ammonia in this reaction?

1. It acts as an Arrhenius acid.
2. It acts as an Arrhenius base.
3. It acts as a Brønsted–Lowry acid.
4. It acts as a Brønsted–Lowry base.

13.

Which solution, when added to 25 cm³ of 0.100 mol dm⁻³ NaOH, produces a buffer solution?

14.

The table shows data on two acid-base indicators:

Which conclusion can be drawn about a solution in which:

• bromocresol green is blue
• phenol red is yellow

15.

When there is a small increase in the amount of CO₂(g) in the atmosphere, the pH of an ocean is maintained by a series of chemical reactions. Which equation maintains the pH in the ocean?

16.

Q16. Which row describes and explains the trend in electronegativity from fluorine to iodine?

17. Which diagram represents the change in ionic radius of the ions of the elements across the third period (Na to Cl)?

18. The diagram represents the Boltzmann distribution of molecular energies of a sample of gas at a given temperature.

As temperature increases, which statements are correct?

1. The maximum of the curve is displaced to the right.
2. The proportion of molecules with energies above any given value increases.
3. The proportion of molecules with any given energy increases.

19.

The conversion of diamond into graphite is slightly exothermic. Diamond does not readily change into graphite.

Which reaction pathway diagram correctly represents this conversion?

20.

Which statement about the effect of a catalyst on a system at equilibrium is correct?

21.

In the reaction between aqueous sodium thiosulfate and dilute acid:

• first order with respect to [acid] at low concentration
• zero order with respect to [acid] at high concentration

Which graph represents the experimental results?

22.

Q22. The use of catalytic converters in car exhaust systems reduces the amount of harmful nitrogen oxides emitted into the atmosphere.

Which statements about the catalytic converter are correct?

1. The catalyst is coated onto a honeycomb surface to provide a smaller surface area to increase the rate of the reaction.
2. The catalyst used is a heterogeneous catalyst which lowers the activation energy for the conversion of NO into N₂.
3. The forces of attraction holding the CO and NO molecules onto the surface of the catalyst are weaker than the forces of attraction holding the product molecules onto the surface.
4. Rhodium can be used as a catalyst in the catalytic converter.

23. In which reaction will the equilibrium yield of the right-hand product be increased by both of the indicated changes in pressure and temperature?

24.

Iodine trichloride, ICl₃, is made by reacting iodine with chlorine. Given:

Find standard enthalpy of formation of solid ICl₃.

25.

The equation for the complete combustion of ethanethiol is:

A 20 cm³ sample of ethanethiol vapour is ignited with 100 cm³ of oxygen. After burning, the gas is cooled to room temperature. The cooled gas is then treated with excess aqueous alkali. What percentage of the final volume of cooled gas dissolves in the alkali?

26.

What is the skeletal formula for 2,2,3-trimethylpentane?

27.

Which molecular formulae could represent molecules that exhibit cis-trans isomerism?

1. C₃H₆BrI
2. C₃H₅I
3. C₃H₄I₂
4. C₃H₄BrI

28.

29.

30.

When egg white is heated, protein molecules are denatured. Which statements describe what happens in this process?

• The hydrogen bonds and induced dipole interactions are broken.
• The peptide bonds are broken by hydrolysis.
• The three-dimensional structure of the molecule changes.

31. A voltmeter connected across a resistor in a circuit gives readings that have high precision but low accuracy.
Which row describes the likely error in readings taken with this voltmeter?

32. An astronomical event in a nova (new star) was estimated to have an energy of 100TJ and a duration of 10µs.
What power was produced in this event?

33. Two vectors, P and Q, have equal components in the x-direction, but the magnitude of P is smaller than the magnitude of Q.
How do the angles that Q and P make with the y-axis, and the magnitudes of Q and P in the y-direction, compare?

34. The diagram shows a rectangle with perimeter P.
The sides of the rectangle, measured with an uncertainty of 0.1cm, are Q = 20.0cm and R = 10.0cm

What is the increasing order of the percentage uncertainty of Q, R and P, starting with the smallest?

35. An astronaut is working on the surface of the Moon. The gravitational field strength g is 1.6ms^–2. He drops a hammer from rest and catches it when it has a speed of 1.8ms^–1 and is 0.50m above the ground. From which height above the ground did he drop the hammer?

36.

37. A ball is projected horizontally and falls under gravity. After time t it has travelled a horizontal distance x and fallen a vertical distance y. Air resistance is negligible.
Which row correctly states the distance travelled horizontally and vertically after time 2t?

38. A firework explodes into many parts after being fired high into the air.
At the time when the explosion takes place, what happens to the total momentum and the total kinetic energy of the system?

39. A train consisting of six wagons each of mass 6.0 × 10⁴ kg is pulled at a constant speed by a locomotive of mass 24 × 10⁴ kg along a straight horizontal track. The horizontal force resisting the motion of each wagon is 4000N

The link between wagons 2 and 3 breaks.
What is the acceleration(ms^–2) of the locomotive immediately after the link breaks?

40. The elastic potential energy stored in a stretched wire can be calculated from a suitable straight‑line graph which has force plotted on the y-axis.
Which measurement of the wire is plotted on the x-axis, and which property of the graph is equal to the elastic potential energy stored in the wire?

41. Three non-parallel forces act on a body so that it is in equilibrium. Which condition is not correct?

42. A flat piece of card of uniform thickness is cut out and marked into squares.
Which labelled point is the centre of gravity of the card?

43. A small coin of mass 10g is placed on a horizontal rotating disc at a distance of 5cm from the centre of the disc. The maximum frictional force between the coin and the disc is 0.2N. What is the largest angular velocity that the disc can have without the coin slipping?

44. Which statement about work done is correct?

45. The function of many machines is to transfer energy from one store to another as efficiently as possible.
Which machine is the most efficient?

46. For an electron beam, the following quantities are known or are easily measured.
● area A, when the beam hits a target
● beam current I
● accelerating potential difference V
● elementary charge e
Which expression gives the rate of arrival of electrons per unit area on the target?

47. What is the definition of the electromotive force (e.m.f.) of a power supply?

48. The diagram shows a circuit in which a microammeter records a current of 0.8µA.

Which row gives the direction of movement of electrons through the microammeter shown in the circuit and the number of these electrons passing through the microammeter in 1 second?

49. A voltage with the square waveform shown in the diagram is applied across a 100Ω resistor

50. A resistor with a value of resistance much greater than R is placed in parallel with a resistor of resistance R.
What is the resistance of the combination?

51. A fixed resistor, a variable resistor, a filament lamp and a cell with negligible internal resistance are arranged in four different circuits.

In how many of these circuits is the brightness of the lamp changed by adjusting the resistance of the variable resistor?

52. A beam of positively charged particles is directed towards one side of a square region that contains a uniform magnetic field.
The magnetic field is perpendicular to the velocity of the particles and the plane of the square.
The field can be varied to any magnitude but is constant in direction.
The region of the magnetic field contains a vacuum.

After travelling through the magnetic field, through how many sides of the square region can the positively charged particles possibly pass?

53. There is a current in a straight wire in the direction PR, as shown in the diagram. P and R are two corners of an imaginary cube, with other corners Q, S, T, U, V and W.

A uniform magnetic field is applied through the cube in direction QP. What is the direction of the magnetic force on PR?

54. The electric current through a cylinder of semiconductor material is supplied by copper wires, as shown in the diagram

The charge carriers in the semiconductor material are electrons. The semiconductor material and the copper have the same cross-sectional area. The table gives details of the number of free electrons per cubic metre in each material.

The drift velocity of electrons through the copper wire is 0.58 mms^–1 . What is the drift velocity of electrons through the semiconductor material?

55.

Between which points is the resistance of the combination a maximum?

56. A beam of electrons enters a region in which there are magnetic and electric fields directed at right angles. It passes straight through without deviation.

A second beam of electrons, travelling twice as fast as the first, is then directed along the same line. How is this second beam deviated?

57. A nucleus, Mg (12,27) , decays by emitting a β-particle. What are the proton number and the neutron number of the new nucleus that is formed by the decay?

58. The mass of a nucleus is X. The total mass of its constituent protons and neutrons is Y. What is the binding energy of the nucleus?

59. The table shows three properties of different types of ionising radiation.

60.