AQA GCSE Synergy Paper 3: Physical sciences Higher November 2021 question paper 8465/3H

This question is about structure and bonding.

Figure 1 represents the electronic structure of an atom of an element.

Name the element in Figure 1.

Give one reason for your answer.

Use the periodic table.

Sodium reacts with fluorine to produce sodium fluoride.

Sodium fluoride is an ionic compound.

An atom of sodium and an atom of fluorine react to form a sodium ion and a fluoride ion.

Complete the dot and cross diagram for the sodium ion and the fluoride ion.

Show the charges on the ions.

Figure 2 represents the structure of sodium fluoride.

Describe how sodium ions and fluoride ions are held together in sodium fluoride.

What is a property of sodium fluoride?

Tick (✓) one box.

Conducts electricity when solid

High melting point

Low boiling point

A student investigated how the resistance of a piece of wire varied with the length of the wire.

Figure 3 shows an ammeter the student could have used in the investigation.

What is the resolution of the ammeter?

Which quantity must stay the same so the wire behaves as an ohmic conductor?

Tick (✓) one box.

Air pressure

Density of the wire

Temperature of the wire

Write down the equation which links current (I), potential difference (V) and resistance (R).

For one length of wire the potential difference across the wire was 1.68 V.

The current in the wire was 0.70 A.

Calculate the resistance of this length of wire.

Figure 4 shows the circuit used in the investigation.

The student plotted a graph of resistance against length of the wire.

Describe a method the student could use to obtain the data needed to plot the graph.

This question is about groups in the periodic table.

Neon and argon are Group 0 elements.

What name is given to Group 0?

Give one similarity of the electronic structure of neon and the electronic structure of argon.

Give one difference between the electronic structure of neon and the electronic structure of argon.

Table 1 shows information about elements in Group 1.

Complete Figure 5.

You should: label both axes plot the data from Table 1.

Figure 5

Give one conclusion from the data in Figure 5 on page 11.

Magnesium and hydrochloric acid react to produce magnesium chloride and hydrogen.

Give the test for hydrogen gas.

Give the result of the test if hydrogen gas is present.

During the reaction between magnesium and hydrochloric acid, hydrogen ions form hydrogen molecules.

The half equation for this process is:

What type of reaction does this half equation show?

Give the reason for your answer.

0.72 g of magnesium reacted completely with dilute hydrochloric acid.

The equation for the reaction is:

Calculate the mass of magnesium chloride produced.

Relative atomic masses (A_r): Mg = 24 Cl = 35.5

This question is about the extraction of metals.

Traditional mining methods extract copper from high-grade copper ores.

Phytomining is a method used to extract copper from low-grade copper ores.

Explain one advantage of using phytomining compared with using traditional mining methods to extract copper.

Do not refer to cost in your answer.

Describe how copper compounds are obtained by phytomining.

Electrolysis is one method of obtaining copper from solutions of copper compounds.

Figure 6 shows the apparatus used.

Graphite is a good conductor of electricity.

Give one other reason why graphite is used for the electrodes.

A gas is produced at the positive electrode. The gas is tested with damp litmus paper. The gas bleaches the damp litmus paper.

Identify the copper compound in solution.

Give one reason for your answer.

Scrap iron is used in a reaction to obtain copper from solutions of copper compounds.

Name this type of reaction.

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

Explain why a mixture rather than pure aluminium oxide is electrolysed.

The positive electrodes are made of carbon.

Explain why the positive electrodes wear away during the process.

Figure 7 shows a boat pulling a person parasailing.

Figure 7 is not drawn to scale.

Write down the equation which links gravitational field strength (g), mass (m) and weight (W).

The weight of the person is 735 N.

Calculate the mass of the person.

gravitational field strength = 9.8 N/kg

The person is moving at a constant velocity.

What is the resultant force acting on the person?

The magnitude of the force of the rope on the person is 5000 N.

Draw a vector diagram on Figure 8 to determine the vertical component and the horizontal component of the force on the rope.

Figure 8

The force of the rope on the person parasailing is 5000 N.

The boat pulls the person for a horizontal distance of 1000 m.

The work done by the force of the rope on the person is not calculated by multiplying 5000 N by 1000 m.

Explain how the work done by the force of the rope on the person could be calculated.

This question is about carbon and carbon compounds.

Carbon forms compounds called alkanes.

Which formula represents an alkane molecule with 8 carbon atoms?

Tick (✓) one box.

C₈H₁₀

C₈H₁₄

C₈H₁₆

C₈H₁₈

Alkanes can be cracked.

Name one method of cracking alkanes.

Explain how cracking alkanes helps to meet the demand for fuels.

Ethene can be produced when alkanes are cracked.

The formula of ethene is C₂H₄

Calculate the simplest whole number ratio by mass of carbon to hydrogen in ethene.

Relative atomic masses (A_r): C = 12 H = 1

Ratio by mass of carbon: hydrogen = ______________: ______________

Carbon exists in different forms.

Which form has each carbon atom bonding with four other carbon atoms?

Tick (✓) one box.

Diamond

Graphene

Graphite

Fullerene molecules are made of carbon atoms.

Give two other features of the structure of fullerene molecules.

A carbon nanotube has:

a length to diameter ratio of 6 900 000: 1

Calculate the length of the carbon nanotube in nm.

Explain why carbon nanotubes are good conductors of electricity.

Figure 9 shows a plan view of the route a car travelled from town P to town Q.

The distance the car travelled is a scalar quantity.

The displacement of the car is a vector quantity.

Describe what is meant by a scalar quantity and a vector quantity.

Determine the displacement of the car when the car has travelled from town P to town Q.

At town Q, the car collided with a stationary van.

Figure 10 shows the two vehicles before and after the collision.

Total momentum was conserved in the collision.

mass of car = 1250 kg mass of van = 3000 kg

Calculate the speed v of the van after the collision.

A thermistor is used in an oven as part of a temperature sensor.

Draw the circuit symbol for a thermistor.

Figure 11 shows how the resistance of the thermistor varies with temperature.

Identify the temperature range when the thermistor is most sensitive to temperature change.

Tick (✓) one box.

Between 50 and 100 °C

Between 100 and 150 °C

Between 150 and 200 °C

Between 200 and 250 °C

The potential difference across the thermistor is 15 V.

The current in the thermistor is 0.015 A.

Calculate the energy transferred by the thermistor in 20 minutes.

The power output of the heating element in the oven is 0.72 kW.

The current in the heating element in the oven is 12 A.

Calculate the resistance of the heating element.

This question is about bonds.

Compare the bonding in hydrogen gas (H₂) with the bonding in copper metal.

Hydrogen reacts with oxygen to produce water.

The equation for the reaction is:

The energy released in forming new bonds is 486 kJ/mol greater than the energy needed to break the existing bonds.

Table 2 shows some bond energy values.

Y is the bond energy of a H‒H bond.

Calculate Y.