AQA GCSE Synergy Paper 4: Physical sciences Higher June 2023 question paper 8465/4H

This question is about hydrocarbon fuels.

The complete combustion of a hydrocarbon fuel produces carbon dioxide and one other product.

Name the other product of the complete combustion of a hydrocarbon fuel.

Do not refer to carbon dioxide.

Describe the test for carbon dioxide.

Give the result if carbon dioxide is present.

The combustion of hydrocarbon fuels releases energy.

A student investigated the energy released by three different fuels A, B and C.

Figure 1 shows the apparatus.

This is part of the method used.

1. Put fuel A in the burner.

2. Pour 100 cm³ of water into the conical flask.

3. Record the temperature of the water.

4. Light the fuel and heat the water for 5 minutes.

5. Record the final temperature of the water.

6. Repeat steps 1 to 5 using fuel B and then using fuel C.

The student also determined the mass of fuel burnt.

Describe how the student could determine the mass of fuel burnt.

Give one control variable in the investigation.

Table 1 shows the results.

Explain how Table 1 shows that fuel C released the most energy per gram of fuel.

The student repeated the investigation with screens around the apparatus.

Figure 2 shows the apparatus with screens.

Give one reason why putting screens around the apparatus could improve the accuracy of the investigation.

How would stirring the water improve the accuracy of the investigation?

A solar cell generates a potential difference when light shines on its surface. A student investigated how the potential difference varied with the light intensity at the surface of the solar cell.

Figure 3 shows some of the equipment used by the student.

The voltmeter displayed the potential difference generated by the solar cell.

The student varied the light intensity by changing the height of the torch above the solar cell.

Figure 4 shows the results.

Describe a method the student could have used to obtain the results shown in Figure 4.

The circuit symbol for a solar cell is:

Figure 5 shows the solar cell in a circuit with an LED and a resistor.

Figure 6 shows how the current in the LED varies with the potential difference across the LED.

What is the range of potential difference values for which the LED emits light in Figure 6 ?

Range of values = ______________________ to ______________________ V

Use the Physics Equations Sheet to answer questions 02.3 and 02.4.

Which equation links current (I), potential difference (V) and resistance (R)?

Tick (✓) one box.

Determine the resistance of the LED when the potential difference across the LED is 2.7 V.

Use Figure 6.

Describe how the resistance of the LED varies as the p.d. increases from 0 V to 3.7 V.

Use data from Figure 6.

Figure 7 shows two different designs of wind turbine.

To generate electricity, the three-blade wind turbine rotates about an axis.

To generate electricity, the bladeless wind turbine oscillates from side to side.

Table 2 gives information about the two designs.

To generate electricity, the bladeless wind turbine oscillates from side to side.

Figure 8 shows the direction of the oscillations of the bladeless wind turbine.

Figure 9 shows how the power output of the bladeless turbine varies with the frequency of the oscillation.

Describe how the power output of the bladeless turbine varies with frequency.

The energy from wind turbines can be used to recharge a battery.

Use the Physics Equations Sheet to answer questions 03.3 and 03.4.

Which equation links charge flow (Q), current (I) and time (t)?

Tick (✓) one box.

Q = I t

Q = I t²

= I² Q t

To fully recharge the battery, a charge of 216 000 C needs to flow through the battery.

The current in the battery is 5.0 A.

Calculate the time taken to fully recharge the battery.

Give the unit.

This question is about metal extraction.

Copper compounds can be extracted from low-grade copper ores using: plants bacteria.

Name the process that uses plants to extract copper compounds from low-grade copper ores.

Name the process that uses bacteria to extract copper compounds from low-grade copper ores.

Why are processes using plants and bacteria now used to extract copper compounds from low-grade copper ores?

Give one advantage of extracting copper compounds using plants and bacteria rather than using traditional methods.

Aluminium is extracted by the electrolysis of a molten mixture of aluminium oxide and cryolite.

Explain why the electrolyte used is a mixture of aluminium oxide and cryolite.

Do not refer to cost in your answer.

Oxygen is produced at the positive electrodes.

Explain why the positive electrodes must be continually replaced.

Figure 10 shows a karate expert breaking a wooden board with one hand.

When the hand hits the wooden board, the initial velocity of the hand is 7.5 m/s.

The change in momentum of the hand is 5.0 kg m/s.

The mass of the hand is 0.80 kg.

Calculate the final velocity of the hand.

Use the Physics Equations Sheet.

As the hand exerts a force on the wooden board, the wooden board exerts a force on the hand.

Explain how Newton’s third law applies to the hand hitting the wooden board.

Figure 11 shows the hand hitting the wooden board. When the hand hits the wooden board, the wooden board bends.

When the hand hits the wooden board, the hand moves through a distance of 1.2 cm while exerting a force on the wooden board.

The work done by the hand is 6.0 J.

Calculate the force the hand exerts on the wooden board.

Use the Physics Equations Sheet.

Hydrogen bromide decomposes to form hydrogen and bromine.

The equation for the reaction is:

The energy needed to break the existing bonds is 103 kJ/mol greater than the energy released in forming new bonds.

Table 3 shows some bond energy values.

Y is the bond energy of a H–Br bond.

Calculate Y.

_ Y = _________________ kJ/mol

Figure 12 shows part of the reaction profile when hydrogen bromide decomposes to form hydrogen and bromine.

Complete Figure 12.

You should: label the axes draw the reaction profile label the reactant and the products label the activation energy.

A student investigated how the extension of a spring varied with the force applied to the spring.

Figure 13 shows the equipment used.

This is the method used.

1. Measure the length of the unstretched spring.

2. Hang the spring from the clamp stand.

3. Hang a mass from the spring.

4. Calculate the weight of the mass.

5. Measure the new length of the spring.

6. Calculate the extension of the spring.

7. Repeat steps 3 to 6 for additional masses.

A spring can be elastically or inelastically deformed.

What does ‘elastically deformed’ mean?

Figure 14 shows the results.

The student concluded:

‘The extension of the spring is directly proportional to the weight up to a point called the limit of proportionality.’

What was the extension of the spring when the spring reached its limit of proportionality?

Determine the spring constant of the spring used by the student.

Use the Physics Equations Sheet.

The mass on the spring is stationarity after the spring has extended.

The force that the mass exerts on the spring is represented by the vector diagram in Figure 15.

Draw an arrow on Figure 15 to show the magnitude and direction of the tension in the spring.

A student investigated the reaction between calcium carbonate and hydrochloric acid.

The equation for the reaction is:

The student investigated the effect of changing the concentration of hydrochloric acid on the rate of the reaction.

Figure 16 shows the apparatus.

This is the method used.

1. Add 50 cm³ of hydrochloric acid to the conical flask.

2. Add 2.0 g of calcium carbonate to the conical flask.

3. Immediately insert the stopper into the conical flask and start the timer.

4. Record the volume of gas collected in the gas syringe every 30 seconds.

5. Stop recording when the volume of gas in the gas syringe does not change.

6. Repeat steps 1 to 5 using different concentrations of hydrochloric acid.

Name the independent variable in this investigation.

Figure 17 shows the results for one concentration of hydrochloric acid.

How does Figure 17 show that the rate of reaction decreases with time?

Explain why the rate of reaction between calcium carbonate and hydrochloric acid decreases with time.

A student throws a ball vertically upwards in the air and catches the ball as it returns

Figure 18 is a velocity-time graph of the ball’s motion after leaving the student’s hand until the ball is caught.

Determine the maximum height the ball reaches.

The distance the ball travels when moving upwards is equal to the distance the ball travels when moving downwards.

Explain how Figure 18 shows that the two distances are equal.

Figure 18 does not include the effect that air resistance would have on the ball when it is in motion.

The graph in Figure 18 is a straight line with a constant gradient.

Explain why the gradient is constant.

Describe two ways the graph would change between 0.0 and 0.70 seconds if the effect of air resistance had been included.

Which displacement-time graph represents the ball’s motion after leaving the student’s hand until the ball is caught?

Tick (✓) one box.

The stopping distance of a vehicle depends on the thinking distance and the braking distance.

What is meant by ‘thinking distance’?

What would increase the thinking distance?

Tick (✓) two boxes.

Ice on the road surface

Poor condition of the brakes

The driver being tired

Using a mobile phone while driving

Wet weather

Figure 19 shows how the braking distance of a new car in 2020 compares with the braking distance of a new car in 1975.

The two cars had the same mass and were driven along a level road in sunny weather.

Explain the difference in braking distance between the two cars.

Use Figure 19.

The 2020 car was driven at a speed of 27 m/s. The brakes were applied until the car stopped.

The speed of the car decreased from 27 m/s to 0 m/s with a constant deceleration.

The mass of the car was 850 kg.

Determine the mean braking force on the car.

Use Figure 19.

Use the Physics Equations Sheet.