Edexcel GCSE Combined Science Paper 4: Chemistry 2 Foundation June 2022 question paper 1SC0/2CF

This question is about elements in group 1 of the periodic table.

Figure 1 shows the symbols of the first three elements in group 1 of the periodic table and their melting points.

Use the periodic table to answer these questions.

Give the symbol of another element in group 1.

Give the atomic number of lithium.

Describe the trend in the melting points of the elements in Figure 1.

The elements in group 1 react very vigorously with water.

A student suggests this method to see what happens when sodium reacts with water.

step 1 put on safety glasses and a laboratory coat

step 2 cut a 2 cm×2 cm2 cm cube of sodium

step 3 put a few drops of water in the container shown in Figure 2

step 4 add the sodium to the water in the container and observe the reaction

Figure 2 shows a diagram of the container the student suggested for step 3.

Give the name of the container shown in Figure 2.

A teacher says that the method is not safe because the reaction is too vigorous.

Explain changes that could be made to step 2 and to step 3 that would make the method safer.

step 2: change and explanation

step 3: change and explanation

Some reactions are exothermic and some reactions are endothermic.

What does an exothermic reaction always give out?

In an experiment, a solid is mixed with a liquid. The temperature change of the mixture is measured.

Figure 3 shows the apparatus that is used.

Give the letter of the piece of apparatus, A, B, C or D, in Figure 3 that is used to measure the temperature.

Give the name of the piece of apparatus B shown in Figure 3.

The piece of apparatus labelled C is made from polystyrene.

State why polystyrene is a better material than glass for this piece of apparatus.

The results of the experiment are given in Figure 4.

Calculate the change in temperature.

Give a sign and a unit in your answer.

temperature change =_........

The solid used in this experiment contained only NH⁺₄ ions and NO^–₃ ions.

Give the formula and the name of the solid.

formula_........

name_........

Figure 5 shows one molecule of a compound obtained from crude oil.

Give the names of the two elements in this molecule.

What is the molecule in Figure 5?

What is the relative formula mass of the compound in Figure 5?

(relative atomic masses: H = 1.0, C = 12)

Crude oil can be separated into different fractions.

Draw one straight line from each fraction to a use of that fraction.

Hydrogen chloride gas and sulfur dioxide gas are dissolved in separate test tubes of water. Blue litmus paper is dipped into each test tube.

State and explain the colour change you would observe in each test tube.

This question is about elements in group 7, the halogens.

Which halogen is a green gas at room temperature and pressure?

Bromine, chlorine and iodine all react with heated iron wool.

Figure 6 shows the speed of these reactions.

When iron wool is heated with chlorine, iron chloride is formed.

Write the word equation for this reaction.

Give the name of the halogen in Figure 6 that is the most reactive with iron.

34.4 % of the mass of iron chloride is iron.

Calculate the mass of iron and the mass of chlorine in 125 g of iron chloride.

mass of iron =_........ g mass of chlorine =_........ g

Alkenes react with halogens.

When iron chloride is added to the reaction mixture, the reaction is much faster but the products are the same.

Use words from the box to complete the sentences.

The iron chloride speeds up the reaction because it is_........

After the reaction, the mass of iron chloride is_........

A student used the apparatus in Figure 7 to investigate the rate of the reaction between a metal and dilute hydrochloric acid.

Pieces of the metal were placed in dilute hydrochloric acid in the flask, and the total volume of gas produced was measured every minute.

Figure 8 shows a graph of the student’s results.

Name a piece of apparatus that would be better to measure the volume of gas produced, instead of the 250 cm³ measuring cylinder.

Give a reason for your answer.

name of apparatus

reason

Calculate the mean rate of production of hydrogen over the first 90 seconds, in cm³ per second.

rate =_........ cm³ per second

The student measured the volume of gas for 10 minutes.

State why the measurements could have been stopped at 9 minutes.

The experiment was repeated, but with acid of a higher concentration.

The rate of reaction was faster.

Explain why the rate of reaction increases when the concentration of acid is increased.

Another student suggests four other ways of increasing the rate of this reaction.

Which one is correct?

The apparatus in Figure 7 can be used to measure the rate of the reaction between marble chips and hydrochloric acid.

The student needs different sized marble chips.

Describe how the student can make small and medium sized marble chips from large chips.

This question is about gases.

When sodium is added to water, hydrogen gas is produced.

Which observation shows that a gas has been produced?

Some damp litmus paper is placed in a gas. The litmus paper is bleached.

Which gas bleaches damp litmus paper?

When calcium carbonate is heated it decomposes.

When 5.000 g of calcium carbonate is heated, the mass of solid remaining is 2.800 g.

Calculate the mass of carbon dioxide that has been released.

Give your answer to three significant figures.

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

A diagram of an atom of helium is shown in Figure 9.

Explain, using Figure 9, why helium is inert.

Helium is used to fill balloons.

State one property of helium, apart from it being inert, that makes it suitable for filling balloons.

*(e) Figure 10 shows the relative amounts of three gases in the early atmosphere compared to the composition of today’s atmosphere.

Natural processes and human activities have altered the relative amounts of these gases in the atmosphere.

Explain how the relative amount of each of the gases in Figure 10 has increased or decreased over time.