Combined Science A (Gateway) · OCR J250 · Chemistry Paper 10 · Higher · June 2018
Iron can be extracted from its ore by heating it with carbon.
Which statement is the correct explanation for this?
A Iron is above carbon in the reactivity series.
B Iron is above copper in the reactivity series.
C Iron is below carbon in the reactivity series.
D Iron is below sodium in the reactivity series.
[1]
Look at the table.
| Nitrogen | Oxygen | Carbon dioxide | Argon | |
| A | 21% | 78% | 0.04% | 0.1% |
| B | 80% | 15% | 4.5% | 0.5% |
| C | 70% | 20% | 9% | 1.0% |
| D | 78% | 21% | 0.04% | 0.9% |
Which row in the table shows the percentages of gases in the present day atmosphere?
[1]
Look at the equation for the reaction between sulfur dioxide and oxygen to make sulfur trioxide.
The reaction forms a dynamic equilibrium.
Which of the following describes dynamic equilibrium?
A All the reactants and products are gases.
B The rate of the backward reaction is greater than the rate of the forward reaction.
C The rate of the forward and backward reactions are equal.
D The rate of the forward reaction is greater than the rate of the backward reaction.
[1]
Fluorine is the most reactive element in Group 7 (Group 17).
Why?
A Fluorine atoms gain an electron more readily than the other Group 7 elements.
B Fluorine is a gas.
C Fluorine exists as diatomic molecules.
D Fluorine atoms lose electrons more readily than the other Group 7 elements.
[1]
Which statement about the fractional distillation of crude oil is correct?
A Diesel leaves the fractionating column at the bottom.
B Petrol leaves the fractionating column at the top.
C The fractionating column is hottest at the top.
D The hydrocarbons in crude oil can be separated because they have different boiling temperatures.
[1]
Magnesium is a more reactive metal than copper.
Why?
A Copper forms positive ions more readily than magnesium.
B Copper is higher in the reactivity series than magnesium.
C Magnesium gains electrons more readily than copper.
D Magnesium loses its outer electrons more easily than copper.
[1]
Which of these solutions will react with each other?
A Sodium bromide and iodine
B Sodium chloride and bromine
C Sodium chloride and iodine
D Sodium iodide and bromine
[1]
Which statement about the halogens (Group 7 elements) is correct?
A Astatine is the most reactive halogen.
B Chlorine has the electronic structure 2.8.7.
C Fluorine is the element with the darkest colour.
D The halogens have the molecular formula X3.
[1]
Why does a catalyst speed up a chemical reaction?
A It causes the reactants to collide less frequently.
B It decreases the overall energy change of the reaction.
C It lowers the activation energy of the reaction.
D It makes more product.
[1]
Which statement about extracting copper by phytoextraction is correct?
A Bacteria in the soil absorb the copper ions.
B Plant ash is equivalent to a high grade ore.
C Plant roots absorb copper metal from the soil.
D The plants are crushed to extract the copper ions.
[1]
Complete the table to show the totals for each column.
[2]
It costs more to transport glasses made from material B.
Suggest a reason why.
[1]
Which material should the company choose?
Justify your answer.
[2]
A student investigates the rate of reaction between magnesium and hydrochloric acid. The reaction gives off hydrogen gas.
The student wants to investigate how changing the concentration of the hydrochloric acid affects the rate of reaction.
Look at her plan.
I will put 0.5 g of magnesium ribbon into the flask.
I will add 50 cm3 of hydrochloric acid.
I will measure how fast the gas is given off.
I will put another 0.5 g of magnesium ribbon into the flask.
I will add 100 cm3 of the same hydrochloric acid.
I will measure how fast the gas is given off.
Another student thinks that the plan will not work and he does not understand exactly what he has to do.
Suggest how the plan for this investigation can be improved.
[4]
The table shows some hydrocarbons from crude oil.
| Name | Formula |
| Methane | CH4 |
| Propane | C3H8 |
| Butane | C4H10 |
Nonane is another hydrocarbon from crude oil.
It contains 9 carbon atoms.
Predict the formula of nonane.
[1]
Write down the name of this homologous series of hydrocarbons.
[1]
A student investigates the rate of reaction between marble chips and hydrochloric acid.
He measures the total mass of carbon dioxide given off for different sizes of marble chips.
Look at a graph of his results.
Which reaction is faster?
Explain how you can tell using data from the graph.
[2]
Explain why changing the size of the marble chips changes the rate of the reaction.
[3]
Look at the diagram.
It shows four processes (1 – 4) which happen in the Earth’s atmosphere and on its surface.
........
........
........
........
[4]
Look at the graphs.
Graph 1 shows how the Earth’s temperature has changed between 1880 and 2010.
Graph 2 shows how the amount of carbon dioxide in the air has changed between 1750 and 2010.
Some scientists believe that graph 1 and graph 2 show that increased levels of carbon dioxide have increased the Earth’s temperature.
Other scientists believe that it is just a natural cycle of change.
Quote data from the graph which supports both of these arguments.
Evidence to support increased temperature of Earth........
Evidence to support a natural cycle........
[2]
Look at the information about three elements X, Y and Z in the Periodic Table.
| Element | X | Y | Z |
| Atomic number | Less than 11 | 11 | More than 11 |
| Melting point (°C) | 181 | 98 | 63 |
| Density (g/cm3) | 0.53 | 0.97 | 0.86 |
| Reaction with water | Reacts quickly making hydrogen | Reacts vigorously making hydrogen | Reacts explosively making hydrogen |
| Energy needed to remove 1 electron from an atom (kJ/mol) | 520 | 496 | 419 |
| Atomic radius (nm) | 0.134 | 0.154 | 0.196 |
| Formula of chloride | XCl | YCl | ZCl |
| Action of heat on carbonates | Breaks down and makes carbon dioxide | No reaction | No reaction |
* Student A thinks that elements X, Y and Z are in the same Group of the Periodic Table.
Student B thinks they are in different Groups of the Periodic Table.
Analyse and explain the information in the table that supports both Student A’s and Student B’s conclusions.
Who do you think is correct?
[6]
Write a balanced symbol equation for the reaction of element Y with water.
Use ‘ Y ’ to represent element Y.
[2]
Aluminium oxide is mixed with cryolite in the electrolysis cell.
Explain why cryolite is used.
[1]
Aluminium is made at the negative electrode (cathode) from aluminium ions, Al3+.
Write a half equation for this reaction. Use e− to represent an electron.
[1]
Oxygen, O2, is made at the positive electrode (anode).
The anodes in the cell have to be replaced every few weeks.
Suggest why.
[2]
Write the overall balanced symbol equation for the electrolytic breakdown of aluminium oxide, Al2O3.
[2]
Look at the equation for the equilibrium reaction between sulfur dioxide, SO2, oxygen and sulfur trioxide, SO3, in a closed system.
Predict the effect of adding more oxygen to the equilibrium mixture.
Explain your answer.
[2]
Predict the effect of increasing the total pressure in the equilibrium mixture.
Explain your answer.
[2]
Predict the effect of increasing the temperature of the equilibrium mixture.
Explain your answer.
[2]
Sulfur dioxide for this reaction is made by burning sulfur.
Calculate the mass of sulfur needed to make 48 tonnes of sulfur dioxide.
Give your answer to 2 significant figures.
The relative atomic mass, Ar, of S is 32.1 and of O is 16.0.
Answer =........ tonnes
[3]
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