OCR Combined Science B Papers 2 and 6 Automock

#1. What is the difference in concentration between pH 6 and pH 4?

10x

1000x

100x

10,000x

1x

#2. The table shows 3 substances and their melting points. Which types of substances could Y be?

Select all that apply:

mixture

compound

element

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

Select all that apply:

Planting trees

Burning fossil fuels

Livestock farming

#4. Which of the following describe the composition of a pure substance?

Select all that apply:

is the not the same in all parts of the substance

Is the same in all parts of the substance - can only be an element

Is the same in all parts of the substance - can be either an element or a compound

#5. Which of the following descriptions matches the Mᵣ of a compound?

The sum of the relative atomic masses of all of the atoms or ions in its formula

The simplest whole number ratio of atoms

The mean mass of an atom compared with carbon-12

#6. What is the chemical symbol for chlorine?

#7. Which type of reaction transfers energy to the surroundings?

Endothermic

Exothermic

Mesothermic

#8. Why is magnesium a better electrical conductor than sodium?

Group 2 magnesium has two spare electrons to donate to the delocalised pool, whereas, sodium atoms only have one electron to donate. This means there are more electrons to carry the charge

Group 1 sodium is less electrically conductive because it quickly forms impurities that prevent efficient conduction

#9. Which of these best describes metallic bonding?

Metal atoms lose their electrons to non-metal atoms which then creates positive and negative ions which are attracted by electrostatic attraction.

Metal atoms lose their electrons to a delocalised pool and all of the metal ions are mutually attracted to the delocalised pool, holding all of the ions together.

Metal atoms share their electrons in order to fill their electron shells, this causes an attraction between the positive nuclei and shared electrons.

#10. How many sulfur atoms will react with two lithium atoms to form an ionic compound?

3

2

1

#11. What is the chemical symbol for magnesium?

#12. Reaction profiles are used to show the energy transfers during reactions. Which type of reaction is shown in this reaction profile?

Ectothermic

Endothermic

Mesothermic

Exothermic

#13. What is the charge of a neutron?

0

-1

+1

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

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

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

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

#15. Are non-metals usually shiny or dull in colour?

Shiny

Dull

#16. Which of the following descriptions matches the term empirical formula?

Represents the simplest integer ratio of atoms or ions of each element in a compound

Is the sum of the relative atomic masses

Represents the actual number of atoms of each element in a molecule

#17. Complete the equation: HCl (aq) + KOH(s) → ….. + …..

Select all that apply:

ClOH

H₂O

KCl

H₂

O

#18. Why is graphite softer than diamond?

Graphite is actually harder than diamond

Graphite is softer because the covalent bonds are weaker between atoms of carbon in graphite than in diamond

Graphite is arranged in sheets with weak intermolecular forces holding them together. These can easily slide, making graphite soft.

#19. Which type of reaction is aerobic respiration?

Mesothermic

Endothermic

Exothermic

Ectothermic

#20. During a neutralisation reaction which salt is formed from sulfuric acid?

Chloride

Borate

Sulfate

Nitrate

Carbonate

#21. Are non-metals usually good conductors of heat?

Yes

No

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

No

Yes

#23. Fill in the blanks: Oxidation refers to the …… of electrons and it occurs at the ……..

Loss, Cathode

Loss, Anode

Gain, Anode

Gain, Cathode

#24. During Ernest Rutherford’s experiments with gold foil, why did some of the particles bounce back?

Alpha particles behave in unpredictable ways and can randomly change direction due to quantum effects

Alpha particles are positively charged, they were deflected when they met the positively charged protons in the nucleus

He fired electrons at the gold foil and when they met protons they were reflected back

#25. The distance travelled by a spot is determined by the solubility of the compound. How does solubility impact distance travelled?

More soluble - greater distance

More soluble - shorter distance

#26. Because mixtures contain more than one substance and each has its own melting point, mixtures melt in which way?

at a specific point

over a range of temperatures

#27. 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 --> filtration tower --> chlorine added --> water pumped to homes

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

#28. What is the freezing point of water?

55˚C

30˚C

100˚C

0˚C

66.5˚C

25˚C

#29. Can Rf values be higher than 1?

No

Yes

Under certain conditions

#30. Determine the empirical formula of glucose – C₆H₁₂O₆.

C₂OH

CHO₂

CH₂O

C₂H₂O

#31. Complete the following equation describing a reaction with a metal carbonate and an acid: metal carbonate + acid → …. + …. + ….

Select all that apply:

ozone

salt

carbon dioxide

oxygen

water

#32. True or false – You cannot use physical processes to separate mixtures into different substances.

False

True

#33. Isotopes of atoms have different numbers of which particles?

Protons

Neutrons

#34. Do non-metals usually have a high or low melting point?

High

Low

#35. What is the chemical symbol for potassium?

#36. Are non-metals usually malleable or brittle?

Malleable

Brittle

#37. True or false – Precipitation reactions can be either exothermic or endothermic.

False

True

#38. Are metals usually good conductors of heat?

No

Yes

#39. Is water an example of a covalent compound?

Yes

No

#40. What are ions?

atoms which have different numbers of protons

atoms which have gained or lost electrons

atoms which have different numbers of neutrons

#41. 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

#42. Which of these is a problem with 3D ball and stick models?

The model does not show that the ions will be constantly vibrating

They do not show how the structure formed and suggest that the electrons in different atoms are different, but they are actually the same

The model shows the atoms as being too far apart and there are no sticks

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

Select all that apply:

Early scientists were in competition to record the highest temperatures

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

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

#44. Which of the following describes the Plum Pudding Model of atomic structure?

A central nucleus containing protons and neutrons, surrounded by electrons at discrete energy levels (shells)

A mass of positively charged material with negatively charged electrons distributed throughout it

#45. Strong acids do what in water? ? two words

#46. Which of these is the stationary phase in paper chromatography?

the ink

the solvent

the paper

#47. What is the charge of an electron?

-1

+1

0

#48. What is the formula for hydrochloric acid?

KOH

HCL

Ca(OH)₂

HNO₃

NaOH

H₂SO₄

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

Select all that apply:

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

Ensuring clean water supplies for vulnerable communities

Carbon capture from the atmosphere and storage underground

Building flood defences

Cutting down forests to give humans a new place to live

Using renewable energies instead of fossil fuels

#50. What state of matter has particles which are close together and vibrate around fixed positions?

solids

gases

liquids

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

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

Gradual climate warming has occurred since the evolution of our species

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

Sometimes

No

Yes

#53. What type of substance is pure gold (Au)?

Element

Compound

Mixture

$fractional distillation diagram$

#54. This image shows the apparatus used during fractional distillation. What is function of the fractionating column?

contains glass rods - is the same temperature throughout - only the desired liquid will reach the condenser

contains glass rods - is hotter at top than bottom - only the desired liquid will reach the condenser

contains glass rods - is hotter at bottom than top - only the desired liquid will reach the condenser

#55. What the the least dense state of matter?

liquids

solids

gases

Bose-Einstein Condensates

#56. What method can we use to separate multiple types of liquids?

#57. Which of these are common properties of giant covalent materials?

Insoluble in water

Low melting/boiling points

Soluble in water

Conduct electricity

High melting/boiling points

Do not conduct electricity

#58. When a mixture of rocks, salt and water is filtered, what will be the residue?

water

rocks

sand

salt

#59. What type of substance is carbon dioxide (CO₂ )?

Compound

Element

Mixture

#60. Neutralisation reactions which occur between an acid and a base are always:

Endothermic

Exothermic

#61. Are metals usually malleable or brittle?

Brittle

Malleable

#62. What is the relative mass of a neutron?

1

1/1840

2

#63. 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?

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

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

#64. What is the formula for sulfuric acid?

NaOH

KOH

HCL

HNO₃

Ca(OH)₂

H₂SO₄

#65. Which of the following are uses for paper chromatography?

Select all that apply:

distinguishing between pure and impure substances

separating insoluble solids

identifying substances by comparing chromatogram patterns to patterns formed by known substances

identifying substances by calculating Rf values

determining the boiling point of a substance

#66. True or false. All atoms of the same element have the same atomic number.

True

False

#67. 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

#68. What is the chemical symbol for iron?

#69. Copper can be purified using electrolysis of copper sulfate solution. For this process we use the setup in the image below. Complete the half equation for the reaction at the anode. Cu → ….. + …..

Cu²⁺ + 2e

SO₃²⁻ + 2e

Cu⁺ + e

#70. What is the relative mass of an electron?

2

0 or 1/1840

1

#71. Filtration and crystallisation are used to separate which types of materials?

separating soluble compounds

separate soluble materials from insoluble materials

separate different types of liquids

#72. Which process can be used to separate water from dissolved salts, whilst keeping both substances?

#73. A soluble base is called?

an alkali

a biscuit

an antacid

#74. Why do simple molecules not conduct electricity?

All simple molecules are in the gaseous state and so electrons are too far apart to transfer a charge

Simple molecules do not have an overall charge, making them unable to carry a charge and conduct electricity.

Simple molecules are aligned in the direction opposite to the flow of current. This means that they oppose the flow of electricity.

#75. What is the name of the phase change from liquid to gas?

condensation

sublimation

freezing

evaporation/boiling

deposition

melting

#76. Why did Ernest Rutherford’s experiments with gold foil demonstrate that most of atoms consists of empty space?

Most of the particles were destroyed when they met protons in the nucleus

Most of the atoms were deflected or bounced back

Most of the atoms passed straight through the foil

#77. Which scientist proposed the Plum Pudding Model?

John Dalton

JJ. Thomson

Ernest Rutherford

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

Select all that apply:

Rising ocean temperatures causing coral bleaching and other adverse effects

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

Extinctions of species unable to migrate or adapt to higher temperatures

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

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

#79. What is the formula for sodium hydroxide?

KOH

HCL

Ca(OH)₂

NaOH

HNO₃

H₂SO₄

#80. Complete the equation: H₂SO₄(aq) + ZnO(s) → …. + ….

Select all that apply:

H₂O (l)

HZnO₄ (s)

H₂SO₄ (aq)

ZnSO₄ (aq)

H₂SO₄ (l)

#81. Calculate the relative formula mass of water. Hydrogen Aᵣ = 1, Oxygen Aᵣ = 16.

#82. Complete the following half equation for a reaction the cathode during electrolysis of molten zinc chloride. Zn²⁺ + ….. → Zn

e

2e

ZnO

Zn

#83. Complete the following half equation for a reaction the cathode during electrolysis of molten lead bromide. Pb²⁺ + 2e → …..

Pb

2Pb

Ld

#84. Which of the following are strong acids?

Select all that apply:

ethanoic acid

nitric acid

boric acid

hydrochloric acid

sulfuric acid

carbonic acid

#85. Copper can be purified using electrolysis of copper sulfate solution. For this process we use the setup in the image below. Complete the half equation for the reaction at the cathode. Cu²⁺ + 2e →

CuO

Cu

SO₄²⁻

#86. H₂SO₄(aq) + Na₂O(s) → …. + ….

Select all that apply:

Na₂SO₄(aq)

2H₂O (l)

MgOH

H₂O (l)

NaOH

#87. The graph shows a heating curve for substance X (red) and substance Y (blue). Is substance Y a pure or impure substance?

Impure

Pure

#88. What is the chemical symbol for sulfur?

#89. What type of substance is the air?

Select all that apply:

Element

Compound

Mixture

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

Select all that apply:

chlorination

alpha particle treatment

UV treatment

ozonation

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

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

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

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

#92. Which types of atoms can be found in a pure piece of gold?

Select all that apply:

gold atoms

carbon atoms

trace amounts of other elements

#93. What is the chemical symbol for iodine?

#94. Paper chromatography is used to separate which types of materials?

separating soluble compounds

separate soluble materials from insoluble materials

separate different types of liquids

#95. During electrolysis which electrode do anions and cations migrate to?

Anions to the cathode, cations to the anode

Anions to the anode, cations to the cathode

GCSE OCR Combined Science B Papers 2 and 6

Good Luck!

Results

#1. What is the difference in concentration between pH 6 and pH 4?

#2. The table shows 3 substances and their melting points. Which types of substances could Y be?

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

#4. Which of the following describe the composition of a pure substance?

#5. Which of the following descriptions matches the Mᵣ of a compound?

#6. What is the chemical symbol for chlorine?

#7. Which type of reaction transfers energy to the surroundings?

#8. Why is magnesium a better electrical conductor than sodium?

#9. Which of these best describes metallic bonding?

#10. How many sulfur atoms will react with two lithium atoms to form an ionic compound?

#11. What is the chemical symbol for magnesium?

#12. Reaction profiles are used to show the energy transfers during reactions. Which type of reaction is shown in this reaction profile?

#13. What is the charge of a neutron?

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

#15. Are non-metals usually shiny or dull in colour?

#16. Which of the following descriptions matches the term empirical formula?

#17. Complete the equation: HCl (aq) + KOH(s) → ….. + …..

#18. Why is graphite softer than diamond?

#19. Which type of reaction is aerobic respiration?

#20. During a neutralisation reaction which salt is formed from sulfuric acid?

#21. Are non-metals usually good conductors of heat?

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

#23. Fill in the blanks: Oxidation refers to the …… of electrons and it occurs at the ……..

#24. During Ernest Rutherford’s experiments with gold foil, why did some of the particles bounce back?

#25. The distance travelled by a spot is determined by the solubility of the compound. How does solubility impact distance travelled?

#26. Because mixtures contain more than one substance and each has its own melting point, mixtures melt in which way?

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

#28. What is the freezing point of water?

#29. Can Rf values be higher than 1?

#30. Determine the empirical formula of glucose – C₆H₁₂O₆.

#31. Complete the following equation describing a reaction with a metal carbonate and an acid: metal carbonate + acid → …. + …. + ….

#32. True or false – You cannot use physical processes to separate mixtures into different substances.

#33. Isotopes of atoms have different numbers of which particles?

#34. Do non-metals usually have a high or low melting point?

#35. What is the chemical symbol for potassium?

#36. Are non-metals usually malleable or brittle?

#37. True or false – Precipitation reactions can be either exothermic or endothermic.

#38. Are metals usually good conductors of heat?

#39. Is water an example of a covalent compound?

#40. What are ions?

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

#42. Which of these is a problem with 3D ball and stick models?

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

#44. Which of the following describes the Plum Pudding Model of atomic structure?

#45. Strong acids do what in water? ? two words

#46. Which of these is the stationary phase in paper chromatography?

#47. What is the charge of an electron?

#48. What is the formula for hydrochloric acid?

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

#50. What state of matter has particles which are close together and vibrate around fixed positions?

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

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

#53. What type of substance is pure gold (Au)?

#54. This image shows the apparatus used during fractional distillation. What is function of the fractionating column?

#55. What the the least dense state of matter?

#56. What method can we use to separate multiple types of liquids?

#57. Which of these are common properties of giant covalent materials?

#58. When a mixture of rocks, salt and water is filtered, what will be the residue?

#59. What type of substance is carbon dioxide (CO₂ )?

#60. Neutralisation reactions which occur between an acid and a base are always:

#61. Are metals usually malleable or brittle?

#62. What is the relative mass of a neutron?

#63. 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?

#64. What is the formula for sulfuric acid?

#65. Which of the following are uses for paper chromatography?

#66. True or false. All atoms of the same element have the same atomic number.

#67. 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?

#68. What is the chemical symbol for iron?

#69. Copper can be purified using electrolysis of copper sulfate solution. For this process we use the setup in the image below. Complete the half equation for the reaction at the anode. Cu → ….. + …..

#70. What is the relative mass of an electron?

#71. Filtration and crystallisation are used to separate which types of materials?

#72. Which process can be used to separate water from dissolved salts, whilst keeping both substances?

#73. A soluble base is called?

#74. Why do simple molecules not conduct electricity?

#75. What is the name of the phase change from liquid to gas?

#76. Why did Ernest Rutherford’s experiments with gold foil demonstrate that most of atoms consists of empty space?

#77. Which scientist proposed the Plum Pudding Model?