Edexcel GCSE Combined Science Paper 3: Chemistry 1 Foundation June 2019 question paper 1SC0/1CF

The three states of matter are solid, liquid and gas.

What is the name of the change of state when a liquid changes into a solid?

A gas was left to cool to form a liquid.

Figure 1 shows how the temperature of the substance changed with time.

From A to B the substance is a gas.

From C to D the substance is a liquid.

State the time when the gas first started to form a liquid.

_........ minutes

Calculate the number of minutes it took from the gas first starting to form a liquid until the substance was completely liquid.

_........ minutes

Figure 2 shows the melting points and boiling points of four substances, W, X, Y and Z.

Using the information in Figure 2

give the letter of the substance that is a solid at 20 °C

give the letter of a substance that is a liquid at 50 °C

The diagrams below show particles in five different structures. The different circles show different particles.

Draw one straight line from each substance to its structure.

Mixtures of substances can be separated using different techniques.

Which of the following is a mixture of substances?

Figure 3 shows the apparatus that a student set up to obtain pure water from ink.

There are three mistakes in the way the apparatus has been set up.

One mistake is that the bulb of the thermometer is too low.

The bulb of the thermometer should be level with the side arm.

Give a reason why the bulb of the thermometer should be level with the side arm.

State one other mistake in Figure 3.

Paper chromatography is used to separate the substances in five different food colourings, P, Q, R, S and T.

Figure 4 shows the chromatogram at the end of the experiment.

The steps needed to carry out the chromatography experiment are listed below. They are not in the correct order.

1 leave the solvent to rise up the paper 2 put solvent in the beaker 3 draw a start line on the piece of paper 4 place the paper in the beaker 5 remove the paper when the solvent is near the top 6 put small spots of the food colourings on the start line

List the steps in the correct order.

The first two steps have been done for you.

Explain, using Figure 4, which food colouring contains the greatest number of coloured substances.

During chromatography of the food colourings, the solvent front moved 8.00 cm and the food colouring R moved 2.30 cm.

Calculate the R_f value for food colouring R. Give your answer to two significant figures.

R_f value =_........

(a) The reactivity of copper, magnesium and zinc was investigated. Each metal was placed separately in dilute hydrochloric acid. The amount of effervescence was observed.

The same mass of metal was used in each experiment. Which piece of apparatus should be used to find the mass of metal used?

State two variables, apart from the mass of the metals, that should be controlled in this investigation.

Magnesium produces the most vigorous effervescence. Copper does not produce any effervescence.

Give the reason why copper does not produce any effervescence.

The magnesium reacts with dilute hydrochloric acid to form magnesium chloride solution and hydrogen gas.

The equation for the reaction is

Mg(s) + 2HCl(aq) MgCl₂(_........ ) + H₂(_........ )

Fill in the missing state symbols in the spaces provided.

Potassium carbonate reacts with dilute sulfuric acid to form potassium sulfate.

Potassium sulfate contains potassium ions, K⁺, and sulfate ions, SO₄²⁻.

Write the formula of potassium sulfate.

Equal volumes of a solution of potassium carbonate were reacted separately with an excess of dilute sulfuric acid solution. Pure dry samples of potassium sulfate were obtained from the resulting solutions.

The experiment was repeated three times using the same conditions.

The masses of potassium sulfate obtained were

experiment 1 = 5.22 g experiment 2 = 5.24 g experiment 3 = 5.21 g

Calculate the mean mass of potassium sulfate obtained, giving your answer to two decimal places.

mean mass of potassium sulfate =_........ g

Metals are extracted from substances naturally occurring in the Earth’s crust.

Which of these metals is usually found uncombined in the Earth’s crust?

Zinc can be extracted by heating zinc oxide with carbon.

The products are zinc and carbon dioxide.

Write the word equation for this reaction.

In this reaction zinc oxide loses oxygen.

State the type of reaction taking place when an oxide loses oxygen.

Aluminium is extracted from aluminium oxide by electrolysis. Aluminium oxide is made up of ions.

The formula of aluminium oxide is Al₂O₃.

Give the number of ions in the formula Al₂O₃.

Complete the balanced equation for the overall reaction by putting numbers in the spaces.

2Al₂O_{3 ........} Al +_........ O₂

The environmental impact of a product is assessed in a life-cycle assessment.

The stages in this assessment are given below. They are not in the correct order.

A disposal of the product B manufacturing the product C obtaining and processing the raw materials D using the product

List the stages of the life-cycle assessment, using letters A, B, C, D, in the correct order from start to finish.

Aluminium can be obtained by recycling aluminium waste.

Give two advantages of obtaining aluminium by recycling aluminium waste rather than mining the raw material and extracting aluminium from that raw material.

In Figure 5, the letters A, E, G, J, X and Z show the positions of six elements in the periodic table.

These letters are not the symbols of the atoms of these elements.

Using the letters A, E, G, J, X and Z

give the letters of the two elements that are non-metals

give the letters of two elements in period 2

give the letter of an element that normally forms an ion with a charge of +1.

Element E has an atomic number of 5. In a sample of E there are two isotopes. One isotope has a mass number of 10 and the other isotope has a mass number of 11.

Explain, in terms of subatomic particles, what is meant by the term isotopes.

All atoms of element E in this sample contain

Element X has an atomic number of 18.

State the electronic configuration of an atom of element X.

In an experiment, 3.5 g of element A reacted with 4.0 g of element G to form a compound.

Calculate the empirical formula of this compound. (relative atomic masses: A = 7, G = 16)

You must show your working.

empirical formula of this compound =_........

An oxygen atom has six electrons in its outer shell.

A hydrogen atom has one electron in its outer shell.

Complete the dot and cross diagram of a molecule of water, H₂O.

Show outer shell electrons only.

(a) Water, acidified with sulfuric acid, is decomposed by electrolysis. The water is decomposed to produce hydrogen and oxygen.

A sample of hydrogen is mixed with air and ignited.

State what would happen.

Throughout the experiment the volume of hydrogen and the volume of oxygen are measured at two-minute intervals.

The results are shown in Figure 6.

Describe, using the data in Figure 6, what the results show about the volumes of hydrogen and of oxygen produced in this experiment.

Molten lead bromide is electrolysed.

The products of this electrolysis are

Calcium nitrate and calcium carbonate are both ionic compounds.

Calcium nitrate mixed with water behaves as an electrolyte. Calcium carbonate mixed with water does not behave as an electrolyte.

Explain, in terms of solubility and movement of ions, this difference in behaviour.