OCR Combined Science A Papers 4 and 10 Automock

#1. Why is there a minimum energy required for reactions to occur?

High energies cause spontaneous rearrangement of particles without impacts between them

High collision energies are more likely to break chemical bonds

#2. Fresh water contains many different contaminants and so must be cleaned before it becomes potable. Which is the correct treatment path?

water from source --> chlorine added --> filtration tower --> sedimentation tank --> storage --> water pumped to homes

water from source --> sedimentation tank --> filtration tower --> chlorine added --> storage --> water pumped to homes

water from source --> filtration tower --> chlorine added --> water pumped to homes

#3. Which of the following are problems that would arise from measuring an extremely slow rate of reaction?

Select all that apply:

Very small changes are difficult to accurately measure

Extremely slow reactions do not always follow the law of conservation of energy

Very slow changes require long-term experiments - costly and may exceed human lifetimes

#4. Which of these is a fast reaction?

Explosions

Photosynthesis

Rusting

#5. How did the oceans form?

Liquid water gradually seeped directly out of the Earths crust, for thousands of years

Liquid water spontaneously formed when the ammonia and and methane in the atmosphere interacted chemically

Water vapour in the atmosphere condensed as the Earth cooled, forming the oceans

#6. Surface area to volume ratio affects rate of reaction. Why is that the case?

With higher surface area to volume ratio, there is more surface where collisions can take place

With higher surface area to volume ratio, the overall temperature of reactants is lower, this leads to increased collision impact when struck

With lower surface area to volume ratio, objects are much hotter and travel faster

#7. Which of these describes the term “rate of reaction”?

The number of particles involved in a reaction in 1 minute

The speed at which reactants are turned into products

The rate of temperature change in the surroundings

#8. Which of the following is the chemical test for oxygen?

An audible squeaky pop is heard when a lit splint is exposed to a test tube full of oxygen

A glowing splint is relit in a test tube filled with oxygen

Oxygen is bubbled through limewater and it turns cloudy when oxygen is present

#9. What is the evidence supporting the idea that there was very little oxygen in the atmosphere in Earth’s early atmosphere?

Select all that apply:

No iron oxide bands in layers of rock are present in deeper (older) layers

Oxygen is not produced by volcanoes

The gravitational field strength of the Earth is not strong enough to hold oxygen in the atmosphere

#10. Why is a spark often needed to start a combustion reaction?

It releases electrons from their shells and they rapidly ignite the fuel

It provides the activation energy needed

It removes excess nitrogen from the surrounding area, making ignition easier

#11. In an experiment to measure the rate of photosynthesis of pondweed in a test tube, the number of bubbles (oxygen) produced per minute is used to determine the rate of reaction. What is this experiment actually measuring?

The concentration of the products of the reaction

The mass of the reactants of the reaction

The volume of the products of the reaction

The mass of the products of the reaction

The volume of the reactants of the reaction

#12. Will exothermic reactions continue if there is no energy input?

No, even if reactants have not run out

Yes, until reactants run out

#13. Greenhouse effect 2) Fill in the blanks: Greenhouse gases such as ……….. , …………. and ……….. absorb infrared radiation from the Earth and re-emit it back to the Earth’s surface, causing warming.

Carbon dioxide, oxygen and water vapour

Carbon dioxide, water vapour and nitrogen

Carbon dioxide, methane and water vapour

#14. Which of the following are commonly used as methods of sterilising fresh water? ? 3

Select all that apply:

ozonation

alpha particle treatment

chlorination

UV treatment

#15. Which evidence provides information about carbon dioxide concentration and global temperatures?

Using the oldest continuous temperature measurements from humans and using computers to predict long term trends with this data

Ice cores which trap atmospheric gases when snow falls producing layers over time

#16. Which processes can we use for purifying sea water?

Select all that apply:

distillation

reverse osmosis

filtration

#17. What is the current composition of the Earth’s atmosphere?

78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% other gases

78% carbon dioxide, 21% oxygen, 0.9% argon, and 0.1% other gases

78% oxygen, 21% nitrogen, 0.9% argon, and 0.1% other gases

#18. Which of the following are effects of climate change?

Select all that apply:

Rising sea levels due to ice in the south pole and in glaciers melting

More extreme weather events (stronger storms, rainfall and droughts)

Rising ocean temperatures causing coral bleaching and other adverse effects

Extinctions of species unable to migrate or adapt to higher temperatures

Lower pH of oceans due to dissolving carbon dioxide producing carbonic acid

#19. Which steps can we take to reduce the impact of climate change on humanity or prevent further climate change?

Select all that apply:

Cutting down forests to give humans a new place to live

Using renewable energies instead of fossil fuels

Carbon capture from the atmosphere and storage underground

Building flood defences

Pumping water to the Sahara Desert and creating a new place to live

Ensuring clean water supplies for vulnerable communities

#20. Is it possible to control the rate of reaction?

Yes

No

#21. Why do historical measurements by humans of global temperature have some uncertainty?

Select all that apply:

Instruments to measure temperature were not very accurate in the past and have gained more resolution over time

The longest continuous record of temperature is only available in one place

Early scientists were in competition to record the highest temperatures

#22. Which geological process formed Earth’s atmosphere?

Volcanism

Glaciation

Earthquakes

Continental drift

#23. Why did the amount of oxygen in the atmosphere increase over time?

Oxygen present in the Earth's mantle, seeped out over time and escaped via deep ocean ridges

Oxygen was released during the Great Oxidation Period from extensive volcanic activity

Plants and other organisms began to perform photosynthesis, producing oxygen gas

#24. What is the name of the process by which salt is removed from water?

demicronation

unsaturation

desalination

#25. Chemical reactions require a high enough collision energy for reactions to take place. What do we call the minimum amount of energy needed for a reaction?

The Introactive energy minimum

PR energy

Reactionary energy

Activation energy

#26. Iron is turned into iron oxide when exposed to the air. This is a process also known as rusting. Is the rate of reaction fast or slow in rusting?

Slow

Fast

#27. How could we accurately monitor the rate of a reaction? ? Three answers

Select all that apply:

By measuring the changes in volume of reactants and products

By measuring the temperature throughout a reaction

By measuring the concentration of reactants and products throughout a reaction

By measuring the changes in mass of reactants and products

#28. Increasing the concentration of solutions increases the rate of reaction, why is this the case?

When solutions are dilute, there are more particles in the same volume

When solutions are more concentrated, the intermolecular forces become weaker and bonds are more easily broken

More collisions take place because there are more particles in the same volume

#29. Which human activities cause increases in the greenhouse gases – carbon dioxide and methane?

Select all that apply:

Planting trees

Livestock farming

Burning fossil fuels

#30. Greenhouse effect 1) Fill in the blanks: Energy from the sun in the form of …….. hits the Earth’s surface and ……. are emitted back towards the atmosphere.

Gravitational waves, ultraviolet waves

Sound waves, ocean waves

Visible/infrared waves, infrared waves

#31. Why do we use distilled water for chemical analysis?

distilled water is cheaper than tap water

tap water contains small amounts of dissolved salts which could contaminate the results

distilled water is warmer so it is better for conducting chemical analysis

#32. Which of the following examples matches the composition of Earth’s early atmosphere?

Mainly carbon dioxide, some water vapour, little or no oxygen and small amounts of other gases

Mainly water vapour, some oxygen, little or no carbon dioxide and small amounts of other gases

Mainly oxygen, some water vapour, little or no carbon dioxide and small amounts of other gases

#33. Will endothermic reactions continue if there is no energy input?

No, even if there are still reactants

Yes, until reactants run out

#34. Does increasing the pressure of gases increase the rate of reaction?

Sometimes

No

Yes

#35. Temperature affects the rate of reaction. Which of the following is the correct description of what happens when temperature changes?

As temperature increases, rate of reaction decreases

Rate of reaction is highest at very high and very low temperatures

As temperature increases, rate of reaction increases

#36. Why may our attempts to mitigate the effects of climate change cause further damage to the environment?

Animals and plants will resist the efforts we take to help them causing distress and loss of ecological productivity

Vulnerable ecosystems may be disrupted in our attempts to improve conditions for humans

Unexpected consequences often follow when we interrupt complex systems that do not fully understand e.g. the atmosphere

#37. On the early Earth, there was a lot of volcanic activity as the planet was cooling down. How can we link this to the formation of the atmosphere?

Measure the gases released by volcanoes and compare them to the composition of the atmosphere over time

Assume that volcanic activity is not relevant to the atmosphere and look for other sources of gases

#38. When there are more frequent collisions between particles, what will happen to the rate of reaction?

It will stay the same

It will increase

It will decrease

#39. Which of these reasons explains why temperature affects rate of reaction?

Reactant particles at lower temperatures are struck by rapidly moving electrons, causing the reaction to happen faster

Reactant particles at higher temperatures move more quickly, collide more often and with enough energy to react

Reactant particles are unaffected by temperature, but the bonds at higher temperatures become weaker leading to an increased rate of reaction

#40. Why did the concentration of carbon dioxide in the atmosphere decrease after the oceans formed?

Carbon dioxide escaped the atmosphere as the Earth's spin increased in speed, causing an increase the centrifugal force

Carbon dioxide was split by photolysis, producing pure carbon which rained down as a solid.

Carbon dioxide dissolved into the oceans and sea organisms used carbon in their shells as calcium carbonate

#41. Which of the following are the main sources of drinking water in the UK?

Select all that apply:

aquifers

lakes

rivers

seawater

#42. What evidence supports the notion that human activities are contributing to climate change?

Gradual climate warming has occurred since the evolution of our species

Correlation between increases in atmospheric temperatures and historic releases of greenhouse gases, due to combustion of fossil fuels

GCSE OCR Combined Science A Papers 4 and 10

Good Luck!

Results

#1. Why is there a minimum energy required for reactions to occur?

#2. Fresh water contains many different contaminants and so must be cleaned before it becomes potable. Which is the correct treatment path?

#3. Which of the following are problems that would arise from measuring an extremely slow rate of reaction?

#4. Which of these is a fast reaction?

#5. How did the oceans form?

#6. Surface area to volume ratio affects rate of reaction. Why is that the case?

#7. Which of these describes the term “rate of reaction”?

#8. Which of the following is the chemical test for oxygen?

#9. What is the evidence supporting the idea that there was very little oxygen in the atmosphere in Earth’s early atmosphere?

#10. Why is a spark often needed to start a combustion reaction?

#11. In an experiment to measure the rate of photosynthesis of pondweed in a test tube, the number of bubbles (oxygen) produced per minute is used to determine the rate of reaction. What is this experiment actually measuring?

#12. Will exothermic reactions continue if there is no energy input?

#13. Greenhouse effect 2) Fill in the blanks: Greenhouse gases such as ……….. , …………. and ……….. absorb infrared radiation from the Earth and re-emit it back to the Earth’s surface, causing warming.

#14. Which of the following are commonly used as methods of sterilising fresh water? ? 3

#15. Which evidence provides information about carbon dioxide concentration and global temperatures?

#16. Which processes can we use for purifying sea water?

#17. What is the current composition of the Earth’s atmosphere?

#18. Which of the following are effects of climate change?

#19. Which steps can we take to reduce the impact of climate change on humanity or prevent further climate change?

#20. Is it possible to control the rate of reaction?

#21. Why do historical measurements by humans of global temperature have some uncertainty?

#22. Which geological process formed Earth’s atmosphere?

#23. Why did the amount of oxygen in the atmosphere increase over time?

#24. What is the name of the process by which salt is removed from water?

#25. Chemical reactions require a high enough collision energy for reactions to take place. What do we call the minimum amount of energy needed for a reaction?

#26. Iron is turned into iron oxide when exposed to the air. This is a process also known as rusting. Is the rate of reaction fast or slow in rusting?

#27. How could we accurately monitor the rate of a reaction? ? Three answers

#28. Increasing the concentration of solutions increases the rate of reaction, why is this the case?

#29. Which human activities cause increases in the greenhouse gases – carbon dioxide and methane?

#30. Greenhouse effect 1) Fill in the blanks: Energy from the sun in the form of …….. hits the Earth’s surface and ……. are emitted back towards the atmosphere.

#31. Why do we use distilled water for chemical analysis?

#32. Which of the following examples matches the composition of Earth’s early atmosphere?

#33. Will endothermic reactions continue if there is no energy input?

#34. Does increasing the pressure of gases increase the rate of reaction?

#35. Temperature affects the rate of reaction. Which of the following is the correct description of what happens when temperature changes?

#36. Why may our attempts to mitigate the effects of climate change cause further damage to the environment?

#37. On the early Earth, there was a lot of volcanic activity as the planet was cooling down. How can we link this to the formation of the atmosphere?

#38. When there are more frequent collisions between particles, what will happen to the rate of reaction?

#39. Which of these reasons explains why temperature affects rate of reaction?

#40. Why did the concentration of carbon dioxide in the atmosphere decrease after the oceans formed?

#41. Which of the following are the main sources of drinking water in the UK?

#42. What evidence supports the notion that human activities are contributing to climate change?

Quick Links

Services

Resources