The three states of matter

Figure 4 shows the changes of state between ice, water and steam.

What is the name of the change of state labelled P in Figure 4?

Which of the following shows the arrangement of particles in ice?

Figure 5 shows the apparatus that can be used to separate a mixture of ethanol and water by fractional distillation.

Name the piece of apparatus labelled R in Figure 5.

Explain the purpose of the piece of apparatus labelled Q in Figure 5.

A student investigates the food dyes used to make the colours W, X, Y and Z in four different sweets.

Figure 6 shows the chromatogram produced.

The solvent front shows how far the solvent moves during the investigation.

Using the information in Figure 6, state which colour is made of only two food dyes.

The R_f value of a spot on the chromatogram can be calculated using the equation R distance moved by the food dye ^f distance moved by solvent front

Using the information in Figure 6, calculate the R_f value of the food dye labelled S.

Give your answer to 2 decimal places.

R_f value of food dye S =_........

Nitrogen, N₂, oxygen, O₂ and fluorine F₂ are all gases.

Nitrogen, oxygen and fluorine are in the same period of the periodic table.

Explain, in terms of electronic configuration, in which period of the periodic table nitrogen, oxygen and fluorine are located.

Fluorine has a boiling point of –188 °C.

Explain why fluorine has a low boiling point.

A mixture of nitrogen and oxygen becomes a liquid when cooled to –200 °C.

Which row shows the changes in energy and movement of the molecules as they are cooled from room temperature to –200 °C?

The mixture of liquid nitrogen and liquid oxygen can be separated.

Which process could be used to separate a mixture of liquid nitrogen and liquid oxygen?

At high temperatures, nitrogen, N₂, can react with oxygen, O₂, to form nitrogen dioxide only.

Write the balanced equation for this reaction.

Figure 1 shows a test tube being heated in a beaker of water.

The test tube contains solid wax.

As the test tube was heated, the solid wax changed to liquid wax.

After heating, the wax was allowed to cool to room temperature.

Figure 2 shows the arrangement of particles in liquid wax.

Draw the arrangement of particles in solid wax in the box in Figure 3.

When the wax cools, it changes from a liquid back to a solid. This change is a physical change.

What name is given to the change of a liquid to a solid?

Explain why the change from a liquid to a solid is a physical change rather than a chemical change.

Another physical change is when a liquid changes into a gas.

Which row shows the movement and arrangement of the particles in a gas?

Suggest why the wax did not change into a gas when the test tube was heated in the beaker of water.

In an experiment, paper chromatography was used to separate the coloured dyes in four different inks, W, X, Y and Z.

Figure 1 shows the chromatogram at the end of the experiment.

The chromatogram shows that only one of the inks contains a single dye.

Which ink contains a single dye?

Which ink contains the greatest number of dyes?

The R_f value of a dye can be calculated using the equation

At the end of the chromatography one dye had moved 3.60 cm and the solvent front had moved 9.20 cm.

Calculate the R_f value for this dye.

Give your answer to 2 decimal places.

The substance used as the solvent in the chromatography was heated for 8 minutes.

Figure 2 shows how the temperature of the substance changed with time.

From A to B the substance was a liquid.

From C to D the substance was a gas.

Give the name of the change when a liquid becomes a gas.

Use Figure 2 to give the temperature of the substance at 4 minutes.

Use Figure 2 to give the time when the substance has completely changed into a gas.

The temperature of the substance at A was 25C.

Calculate the temperature rise of the substance from A to D.

Crystals of copper sulfate are prepared by reacting copper oxide, a base, with dilute sulfuric acid.

Name the other product of this reaction.

During the experiment, a spatula measure of copper oxide, a black powder, is added to warm, dilute sulfuric acid in a beaker.

When the mixture is stirred, the black powder disappears and the mixture turns pale blue.

The student then adds more copper oxide until the maximum amount of copper sulfate is formed without wasting copper oxide.

Explain how the student knows when to stop adding copper oxide.

The reaction produces an aqueous solution of copper sulfate.

What is the best way to obtain crystals of copper sulfate from an aqueous solution?

When some water is removed from the aqueous solution of copper sulfate, crystals of copper sulfate are made.

Describe how the arrangement and movement of the particles change as crystals are formed from a solution.

In this reaction, copper oxide, CuO, forms copper sulfate, CuSO₄.

Explain, in terms of electrons, whether the copper in copper oxide has been oxidised, has been reduced, or has not been oxidised or reduced.

In another experiment, a copper sulfate solution with a concentration of 39.875 g dm^–3 is used.

Calculate the mass of copper sulfate dissolved in 0.300 dm³ of this solution.

Figure 3 shows a metal spoon and two test tubes being heated in a water bath.

One test tube contains a piece of chocolate, the other some liquid egg white.

After heating, the spoon, the chocolate and the egg white are allowed to cool to room temperature.

Figure 4 shows the state of the three different substances before heating, when hot and after cooling.

Describe the differences in the arrangement and movement of the particles in a solid and in a liquid.

difference in arrangement of particles

difference in movement of particles

Give a reason why the metal spoon has not changed state during the experiment.

Explain how we know the change to the egg white is a chemical change rather than a physical change.

If liquid water is cooled below 0 °C it turns into the solid, ice.

Give the name for the change of state from liquid to solid.

Here are five statements about ice and water.

Place ticks in boxes by the two statements that are correct.

Figure 2 shows a label from a bottle of drinking water.

Explain why this drinking water should not be described as pure water.

State the information from Figure 2 that shows that the drinking water is neutral.

Calculate the mass of calcium ions in 250 cm³ of this drinking water.

State how you know that calcium is a metal from its position in the periodic table.

In the 19th century, Mendeleev arranged the elements known at the time to form his periodic table. Mendeleev’s periodic table is different from the modern periodic table.

State one difference between Mendeleev’s periodic table and the modern periodic table.

Aluminium oxide reacts with hydrochloric acid to form a salt and water.

State the name of the salt formed.

In this reaction aluminium oxide is a base.

State the type of reaction that takes place when an acid reacts with a base.

Gallium, Ga, is in the same group of the modern periodic table as aluminium.

The formula of aluminium oxide is Al₂O₃.

Predict the formula of gallium oxide.

Gallium oxide has a very high melting point. Gallium oxide does not conduct electricity when solid but does conduct electricity when molten.

What type of substance is gallium oxide?

Figure 5 shows the changes of state for gallium and the arrangement of particles in liquid gallium.

Complete the boxes for solid gallium and gaseous gallium by drawing the arrangement of the particles in each of these physical states.

Give the name of the change of state labelled Y in Figure 5.

Gallium metal is a conductor of electricity.

Explain how metals conduct electricity.

An ink is a mixture of coloured substances dissolved in water.

Which method is used to separate the coloured substances in the ink?

The apparatus shown in Figure 9 can be used to separate water from ink.

Cold water flows through the condenser.

On Figure 9 use arrows to show where the water should flow in and where it should flow out.

Explain why a condenser is used.

The flask was heated with a Bunsen burner.

Give the name of an alternative piece of apparatus that could be used to heat the flask.

The particles in the ink in the flask can be shown as in Figure 10.

In the boxes below, draw the arrangement of particles that would be expected at A and B shown in Figure 9.

Changes of state between the three states of matter are shown in Figure 11.

The changes shown are physical changes.

Explain why these changes are called physical changes rather than chemical changes.

(a) Hydrogen burns in air at a temperature well above 100 °C to form water.

The boiling points of hydrogen and water are shown in Figure 15.

Use this information to add the missing state symbols to the equation for the reaction taking place as the hydrogen burns.

The atom economy for the reaction in (i) is 100%.

State how the equation shows that the atom economy is 100%.

Lead can be obtained by heating its oxide with carbon. The balanced equation for the reaction is

Calculate the atom economy for the production of lead in this reaction. (relative atomic masses: C = 12, O = 16, Pb = 207 relative formula masses: PbO = 223, CO₂ = 44)

Give your answer to two significant figures.

In an experiment to produce lead, 7.67 g of lead are obtained. The theoretical yield of lead for the experiment is 11.80 g.

Calculate the percentage yield of lead in this experiment.

In most reactions, the percentage yield of any product is less than 100%.

Give two reasons why the percentage yield is less than 100%.

Which of the following substances will be a solid at 20 C and will melt when placed in a beaker of hot water at 80 C?

A student set up the apparatus shown in Figure 4 to obtain pure water from sea water by distillation.

Explain how the water in sea water separates to produce the pure water in this apparatus.

Explain how the apparatus could be improved to increase the amount of pure water collected from the same volume of sea water.

A substance is heated at a constant rate and its temperature is taken every minute. During the heating, the substance undergoes one change of state.

The results are shown on the graph in Figure 5.

Explain the shape of the graph in terms of the changes in the movement and arrangement of the particles as the substance is heated.