Edexcel GCSE Combined Science Paper 4: Chemistry 2 Higher June 2019 question paper 1SC0/2CH

Most of the fuels used today are obtained from crude oil.

Which statement about crude oil is correct?

Crude oil is separated into several fractions by fractional distillation. Two of these fractions are kerosene and diesel oil.

State a use for each of these fractions.

kerosene_........

diesel oil_........

Figure 1 shows where the fractions kerosene and diesel oil are produced in the fractionating column.

Kerosene is obtained higher up the column than diesel oil. Kerosene and diesel oil fractions have slightly different properties.

Choose a property. State how this property for kerosene compares with the property for diesel oil.

property_........

comparison_........

Figure 2 shows the formulae of a molecule of butane and of a molecule of pentane. Butane and pentane are neighbouring members of the same homologous series.

Explain, using these formulae, why butane and pentane are neighbouring members of the same homologous series.

Butane has the formula C₄H₁₀.

Calculate the mass of carbon in 100 g of butane.

Give your answer to three significant figures.

(relative atomic masses: H = 1.00, C = 12.0; relative formula mass: C₄H₁₀ = 58.0)

You must show your working.

mass of carbon =_........ g

An aluminium atom has the atomic number 13 and the mass number 27.

Which row shows the numbers of subatomic particles present in an

Magnesium burns in excess oxygen to form magnesium oxide. The balanced equation for this reaction is

Starting with 1.35 g of magnesium, calculate the maximum mass of magnesium oxide that could be formed in this reaction. (relative atomic masses: O = 16.0, Mg = 24.0)

You must show your working.

mass of magnesium oxide =_........ g

Chlorine reacts with hydrogen to form hydrogen chloride.

Write the balanced equation for this reaction.

Sodium reacts with chlorine to form sodium chloride.

The electronic configuration of the sodium atom is 2.8.1 and the electronic configuration of the chlorine atom is 2.8.7.

Give the electronic configurations of the ions formed.

Na⁺_........

Carbon dioxide is one of the gases in the Earth’s atmosphere. The percentage of carbon dioxide in the Earth’s atmosphere has changed over time.

Which row of the table shows the approximate percentage of carbon dioxide thought to be in the Earth’s early atmosphere and how this percentage changed to form the Earth’s atmosphere today?

The actual percentage of carbon dioxide in the Earth’s atmosphere today varies.

Explain two factors that cause the percentage of carbon dioxide in today’s atmosphere to vary.

factor 1_........

Carbon dioxide is a simple molecular, covalent compound.

It has a low boiling point of –78.5C.

Explain why carbon dioxide has a low boiling point.

Calculate the number of molecules in 0.11 g of carbon dioxide.

Give your answer to two significant figures.

(relative formula mass: CO₂ = 44 Avogadro constant = 6.0210²³)

number of molecules =_........

Some of the elements in the periodic table are metals.

The electronic configuration of a metal is 2.8.3

Which row shows the group and period of the periodic table where this metal is found?

Lithium, potassium and rubidium are alkali metals.

Describe what you would see when a small piece of rubidium is dropped on to water.

The electronic configuration of lithium is 2.1 The electronic configuration of potassium is 2.8.8.1 Lithium is less reactive than potassium.

Explain, in terms of their electronic configurations, why lithium is less reactive than potassium.

Lithium has two naturally occurring isotopes, lithium‑6 and lithium‑7.

A sample of lithium contains 7.59 % of lithium‑6 92.41% of lithium‑7.

Calculate the relative atomic mass of lithium in this sample.

Give your answer to two decimal places. You must show your working.

relative atomic mass of lithium =_........

Calcium carbonate reacts with dilute hydrochloric acid to produce calcium chloride, water and carbon dioxide.

A student wanted to measure the amount of gas produced in two minutes.

The student suggested that this could be done by counting the number of bubbles formed. However, the bubbles are produced too quickly to count them.

Figure 3 shows a conical flask in which the calcium carbonate and dilute hydrochloric acid are reacting.

Complete Figure 3 to show the apparatus that could be used to measure accurately the volume of gas given off in two minutes.

The reaction between calcium carbonate and dilute hydrochloric acid is exothermic.

Explain, in terms of bond breaking and bond making, why some reactions are exothermic.

*(c) An investigation was carried out into the rate of reaction of calcium carbonate with dilute hydrochloric acid.

5.0g of small lumps of calcium carbonate were reacted with 50 cm³ of 0.50 mol dm^–3 hydrochloric acid. Another 5.0 g of the same sized lumps of calcium carbonate were reacted with 50cm³ of 1.0 mol dm^–3 hydrochloric acid. The volume of gas collected in two minutes was recorded for each experiment.

The two experiments were then repeated, each using 5.0 g of large lumps of calcium carbonate.

Figure 4 shows the results.

Explain, in terms of collision of particles, how these results show the effect of the size of the lumps of calcium carbonate and the effect of the concentration of the acid on the rate of this reaction.

Fluorine, chlorine, bromine, iodine and astatine are elements in group 7.

Describe the test to show that a gas is chlorine.

Bromine reacts with hydrogen to form hydrogen bromide. Hydrogen bromide dissolves in water to form a solution.

State the name of the solution formed.

There is a trend in the colour and the state of the halogens at room temperature.

Predict the colour and state of astatine at room temperature.

colour_........

state_........

Bromine, chlorine and iodine are dissolved in water to make aqueous solutions. Potassium iodide solution is added to each of these solutions.

Figure 5 shows the observations.

Explain the observations shown in the table.

Fluorine reacts vigorously with iron to produce iron(III) fluoride, FeF₃.

Write the balanced equation for this reaction.