Reactions of acids

This question is about acids.

A student investigated the volume of an alkali needed to react completely with

Figure 10 shows the apparatus.

This is the method used.

1. Add 25 cm³ of the acid to a beaker.

2. Add a piece of universal indicator paper to the acid.

3. Add the alkali drop by drop to the acid until the universal indicator paper changes colour to green.

4. Record the number of drops of alkali added.

The method does not give an accurate volume of alkali needed to react completely with the acid.

Suggest two improvements to the method.

What is the pH of the solution when the universal indicator paper turns green?

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What name is given to the reaction between an acid and an alkali?

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Which ion do all acids contain?

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Name the acid that reacts with sodium hydroxide to produce sodium nitrate.

Figure 11 shows a reaction profile for the reaction between an acid and an alkali.

What do labels A and B represent on Figure 11 ?

Choose the answers from the box.

Acids also react with insoluble solid substances to produce salt solutions.

When making a salt solution, excess solid is added to the acid.

Draw the apparatus used to separate the excess solid from the salt solution by filtration.

The apparatus should collect:

• the excess solid

• the salt solution.

Solid X reacts with hydrochloric acid to produce zinc chloride and hydrogen gas.

Name solid X.

This question is about bonding and structures.

Figure 10 represents two models of sodium chloride.

Give two limitations of model A compared with model B.

Aluminium sulfate consists of the ions:

What is the formula of aluminium sulfate?

Metals have metallic bonding.

Suggest one reason why aluminium metal conducts electricity better than sodium metal.

Silicon dioxide and the polymer poly(ethene) are solid substances.

Compare silicon dioxide with the polymer, poly(ethene).

Answer in terms of structure and bonding.

A student investigated the temperature change when different masses of zinc were added to copper sulfate solution.

Figure 5 shows the apparatus.

This is the method used.

1. Pour 50 cm³ of copper sulfate solution into a polystyrene cup.

2. Measure the starting temperature of the copper sulfate solution.

3. Add 1.0 g of zinc.

4. Stir the mixture.

5. Measure the highest temperature reached.

6. Repeat steps 1 to 5 two more times.

7. Repeat steps 1 to 6 with different masses of zinc.

The student varied the mass of zinc.

What type of variable is the mass of zinc?

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The word equation for the reaction is:

zinc + copper sulfate → salt A + copper

What is the name of salt A ?

The temperature of the solution increases when zinc reacts with copper sulfate solution.

Give two other observations that can be made when zinc reacts with copper sulfate solution.

Figure 6 shows the highest temperature reached in one experiment.

Complete Table 3.

Use Figure 6.

A teacher repeated the investigation using a digital thermometer.

Table 4 shows the results.

Calculate value B in Table 4.

The range of the results is the minimum value of temperature increase to the maximum value of temperature increase.

What is the range of temperature increase for the experiment with 2.0 g of zinc?

One of the results for 3.0 g of zinc is anomalous.

Which result is anomalous?

Suggest one reason why this result is anomalous.

Magnesium chloride is a soluble salt.

Magnesium reacts with hydrochloric acid to produce magnesium chloride and a gas.

Which gas is produced?

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Magnesium chloride (MgCl₂) can be electrolysed when molten.

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Magnesium chloride contains Mg²⁺ ions and Cl^– ions.

Name the product at each electrode when molten magnesium chloride is electrolysed.

A student investigated the reactivity of three metals: copper, magnesium and iron.

The student mixed each metal with each metal chloride solution.

Table 6 shows the results.

What is the order of reactivity for copper, magnesium and iron?

Give two reasons for your answer.

Use Table 6.

When heated 0.72 g of magnesium reacts with iron oxide to produce 2.32 g of products.

Calculate the mass of iron oxide that reacts with 0.72 g of magnesium.

Nitric acid (HNO₃) is a strong acid.

What is meant by a ‘strong acid’?

Nitric acid is used as a dilute aqueous solution.

What is meant by ‘dilute aqueous solution’?

10 cm³ of a nitric acid solution has a pH of 1

Water is added to the nitric acid solution to change the pH of the nitric acid solution to pH 3

How does the hydrogen ion concentration change?

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Write the ionic equation for the reaction between an acid and an alkali.

The equation shows the reaction between magnesium carbonate and nitric acid.

What is the ratio of the number of moles of magnesium carbonate to the number of moles of nitric acid in the reaction?

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A student mixed some magnesium carbonate with excess nitric acid.

The student then added two drops of universal indicator to the solution.

What colour was the solution after the addition of universal indicator?

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A student investigated the temperature change when different masses of

magnesium carbonate were reacted with excess nitric acid.

Figure 6 shows the apparatus.

This is the method used.

1. Pour 50 cm³ of nitric acid into a polystyrene cup.

2. Measure the temperature of the solution.

3. Add 0.50 g of magnesium carbonate.

4. Stir the mixture.

5. Measure the temperature.

6. Repeat steps 1 to 5 with different masses of magnesium carbonate.

Give two improvements to the method to produce more accurate results.

Do not refer to improvements to the apparatus in your answer.

This question is about carbon dioxide.

Carbon dioxide is soluble in water and forms an acidic solution.

Which ion makes the solution acidic?

Name an indicator that could be used to test if the solution is acidic. Give the result of the test.

Figure 14 shows the mass of carbon dioxide that will dissolve in 1 dm³ of water

at different temperatures.

How does the solubility of carbon dioxide change as the temperature of the

Tick (✓) one box.

Carbon dioxide dissolves in water to form an acidic solution. How does the pH of the solution change as the temperature of the water increases?

Tick (✓) one box.

Calcium carbonate reacts with hydrochloric acid to produce carbon dioxide. The equation for the reaction is:

What is the state symbol (x) in the equation? Tick (✓) one box.

Figure 15 shows equipment a student used for an investigation.

The student investigated the volume of carbon dioxide produced when different

masses of calcium carbonate react with hydrochloric acid. Describe a method the student could use.

Lithium hydroxide reacts with sulfuric acid to produce lithium sulfate. The equation for the reaction is:

What type of reaction is this?

Relative atomic masses (A_r): H = 1 O = 16 S = 32

Relative atomic mass (A_r): O = 16

Give your answer to 2 significant figures.

A solution of lithium sulfate contains 0.30 g of lithium sulfate in 25 cm³. Calculate the concentration of lithium sulfate in g/dm³.

This question is about carbon dioxide.

Carbon dioxide is soluble in water and forms an acidic solution.

Which ion makes the solution acidic?

Name an indicator that could be used to test if the solution is acidic. Give the result of the test.

Figure 1 shows the mass of carbon dioxide that will dissolve in 1 dm³ of water

at different temperatures.

How does the solubility of carbon dioxide change as the temperature of the

Tick (✓) one box.

Carbon dioxide dissolves in water to form an acidic solution. How does the pH of the solution change as the temperature of the water increases?

Tick (✓) one box.

Calcium carbonate reacts with hydrochloric acid to produce carbon dioxide. The equation for the reaction is:

What is the state symbol (x) in the equation? Tick (✓) one box.

Figure 2 shows equipment a student used for an investigation.

The student investigated the volume of carbon dioxide produced when different

masses of calcium carbonate react with hydrochloric acid. Describe a method the student could use.

Lithium hydroxide reacts with sulfuric acid to produce lithium sulfate. The equation for the reaction is:

What type of reaction is this?

Relative atomic masses (A_r): H = 1 O = 16 S = 32

Relative atomic mass (A_r): O = 16

Give your answer to 2 significant figures.

A solution of lithium sulfate contains 0.30 g of lithium sulfate in 25 cm³. Calculate the concentration of lithium sulfate in g/dm³.

Acids react with some metals to produce soluble salts. A student adds magnesium to hydrochloric acid until no more acid reacts and

The equation for the reaction is:

The reaction between magnesium and hydrochloric acid is a redox reaction. Explain what happens to the magnesium atoms in this reaction.

0.72 g of magnesium is added to 100 cm³ of hydrochloric acid. The hydrochloric acid is in excess. Calculate the concentration of the magnesium chloride (MgCl₂) solution produced

This question is about hydrogen chloride and sodium hydroxide.

A chlorine atom has 7 electrons in the outer shell. A hydrogen atom has 1 electron in the outer shell. Figure 4 represents part of a dot and cross diagram for a molecule of hydrogen chloride.

Complete the dot and cross diagram. Use dots (ο) and crosses (x) to represent electrons. You should show only the electrons in the outer shells.

Hydrogen chloride dissolves in water to produce hydrochloric acid. Hydrochloric acid reacts with sodium hydroxide solution. Complete the word equation for the reaction between hydrochloric acid and sodium hydroxide.

hydrochloric acid + sodium hydroxide → + water

Solutions of hydrochloric acid and sodium hydroxide are reacted and the temperature change is recorded.

In the reaction, 3.65 g of hydrogen chloride reacts with 4.00 g of sodium hydroxide. 1.80 g of water is produced. Calculate the mass of the other product.

Figure 5 shows part of the thermometer used to measure the temperature.

What is the temperature reading on the thermometer?

In the reaction, the temperature increases. What type of reaction is happening when the temperature increases?

Sodium hydroxide is an alkali. Which two ions are in sodium hydroxide solution? Tick (✓) two boxes.

This question is about salts. Green copper carbonate and sulfuric acid can be used to produce blue copper sulfate crystals.

Excess copper carbonate is added to sulfuric acid. Give three observations you would make.

How can the excess copper carbonate be removed?

The pH of the solution changes during the reaction. What is the pH of the solution at the end of the reaction?

Copper carbonate and sulfuric acid react to produce copper sulfate. What type of reaction is this?

Ammonium nitrate is a salt. Figure 13 shows the maximum mass of ammonium nitrate that can dissolve in 100 cm³ of water at different temperatures.

A student adds ammonium nitrate to water at 80 °C until no more dissolves. The student cools 100 cm³ of this solution of ammonium nitrate from 80 °C to 20 °C to produce crystals of ammonium nitrate.

Determine the mass of ammonium nitrate that crystallises on cooling 100 cm³ of this solution from 80 °C to 20 °C

Plan an investigation to find the order of reactivity of three metals. You should use the temperature change when each metal reacts with hydrochloric acid.

This question is about salts. Green copper carbonate and sulfuric acid can be used to produce blue copper sulfate crystals.

Excess copper carbonate is added to sulfuric acid. Give three observations you would make.

How can the excess copper carbonate be removed?

The pH of the solution changes during the reaction. What is the pH of the solution at the end of the reaction?

Copper carbonate and sulfuric acid react to produce copper sulfate. What type of reaction is this?

Ammonium nitrate is a salt. Figure 1 shows the maximum mass of ammonium nitrate that can dissolve in 100 cm³ of water at different temperatures.

A student adds ammonium nitrate to water at 80 °C until no more dissolves. The student cools 100 cm³ of this solution of ammonium nitrate from 80 °C to 20 °C to produce crystals of ammonium nitrate.

Determine the mass of ammonium nitrate that crystallises on cooling 100 cm³ of this solution from 80 °C to 20 °C

Acids react to produce salts. Universal indicator is added to water and then nitric acid is added to the mixture.

Give the colour change when nitric acid is added to the mixture of universal indicator and water. Tick (✓) one box.

What happens to the pH of water when nitric acid is added? Tick (✓) one box.

What is the state symbol for nitric acid?

Zinc carbonate reacts with nitric acid.

The word equation for the reaction is: zinc carbonate + nitric acid → zinc nitrate + water + carbon dioxide white solid colourless solution

Give two observations that would be made when zinc carbonate is added to nitric acid until the zinc carbonate is in excess.

The formula of the zinc ion is Zn²⁺ The formula of the nitrate ion is NO₃^– What is the formula for zinc nitrate? Tick (✓) one box.

Acids react with insoluble metal oxides to produce salts. Plan a method to produce a pure, dry sample of the soluble salt copper chloride from an acid and a metal oxide.

Acids react to produce salts. Universal indicator is added to water and then nitric acid is added to the mixture.

Give the colour change when nitric acid is added to the mixture of universal indicator and water. Tick (✓) one box.

What happens to the pH of water when nitric acid is added? Tick (✓) one box.

What is the state symbol for nitric acid?

Zinc carbonate reacts with nitric acid.

The word equation for the reaction is: zinc carbonate + nitric acid → zinc nitrate + water + carbon dioxide white solid colourless solution

Give two observations that would be made when zinc carbonate is added to nitric acid until the zinc carbonate is in excess.

The formula of the zinc ion is Zn²⁺ The formula of the nitrate ion is NO₃^– What is the formula for zinc nitrate? Tick (✓) one box.

Acids react with insoluble metal oxides to produce salts. Plan a method to produce a pure, dry sample of the soluble salt copper chloride from an acid and a metal oxide.

This question is about acids and bases.

What is the pH of sulfuric acid? Tick (✓) one box.

An acid reacts with zinc to produce zinc chloride and hydrogen. Which acid reacts with zinc to produce zinc chloride? Tick (✓) one box.

What type of substance is zinc chloride? Tick (✓) one box.

An alkali is a base in solution. Which compound is an alkali? Tick (✓) one box.

The formula of the copper ion is Cu²⁺ The formula of the oxide ion is O^2– What is the formula of copper oxide? Tick (✓) one box.

A student reacts an acid with copper oxide.

The reaction between the acid and copper oxide is very slow at room temperature. How could the student speed up the reaction?

Complete the sentence to show how the student makes sure that all the acid reacts. Choose the answer from the box.

The student adds copper oxide to the acid until the copper oxide is.

The student filters the unreacted copper oxide from the solution. Which apparatus does the student use? Tick (✓) one box.

What process is used to produce crystals of a salt from a salt solution?

This question is about acids, alkalis and bases. A student reacted zinc oxide powder with hydrochloric acid to produce zinc chloride solution.

Complete the equation for the reaction by writing the state symbols.

Give one way that the student could speed up the reaction between zinc oxide powder and hydrochloric acid.

Hydrochloric acid was the limiting reactant.

How could the student know when all the hydrochloric acid has reacted?

How could the student obtain zinc chloride solution from the reaction mixture when all the hydrochloric acid has reacted?

Describe how zinc chloride crystals are produced from zinc chloride solution.

Sulfuric acid and sodium hydroxide react to produce sodium sulfate.

Sulfuric acid is gradually added to sodium hydroxide solution. The pH of the mixture changes as the sulfuric acid is added until in excess. Suggest the pH at:

• the start before sulfuric acid is added

• the end when sulfuric acid is in excess.

Complete the symbol equation for the preparation of sodium sulfate. You should balance the equation.

A solution of hydrochloric acid had a hydrogen ion concentration of 1.0 mol/dm³ Water was added to the hydrochloric acid until the pH increased by 1 What was the hydrogen ion concentration of the hydrochloric acid after water had been added? Tick (✓) one box.

This question is about salts and electrolysis. A student wants to make copper chloride crystals. The student adds excess copper oxide to some hot acid. The student stirs the mixture.

Which acid should the student use? Tick (✓) one box.

Suggest how the student would know that excess copper oxide has been added.

There are four more stages, A, B, C and D, to make copper chloride crystals. The stages A, B, C and D are not in the correct order. Stage A Partially evaporate by heating with a water bath Stage B Filter the mixture into an evaporating basin Stage C Leave to crystallise Stage D Remove and dry the crystals

Put stages A, B, C and D in the correct order.

Molten copper chloride can be electrolysed. State the product at each electrode when molten copper chloride is electrolysed.

Negative electrode Positive electrode

A solution of copper chloride is electrolysed. Figure 3 shows a graph of the increase in mass of the negative electrode. This increase is shown over a time of 10 minutes.

Calculate the gradient of the line in Figure 3. Use the equation:

Aluminium is produced by electrolysis of a molten mixture. Complete the sentence. Choose the answers from the box.

This question is about reactions of metals. Figure 7 shows what happens when calcium, copper, magnesium and zinc are added to hydrochloric acid.

What is the order of decreasing reactivity of these four metals? Tick (✓) one box.

A student wants to make a fair comparison of the reactivity of the metals with hydrochloric acid.

Name two variables that must be kept constant.

What is the independent variable in this reaction?

Predict the reactivity of beryllium compared with magnesium. Give a reason for your answer. Use the periodic table.

A solution of hydrochloric acid contains 3.2 g of hydrogen chloride in 50 cm³ Calculate the concentration of hydrogen chloride in g per dm³

This question is about reactions of metals. Figure 1 shows what happens when calcium, copper, magnesium and zinc are added to hydrochloric acid.

What is the order of decreasing reactivity of these four metals? Tick (✓) one box.

A student wants to make a fair comparison of the reactivity of the metals with hydrochloric acid.

Name two variables that must be kept constant.

What is the independent variable in this reaction?

Predict the reactivity of beryllium compared with magnesium. Give a reason for your answer. Use the periodic table.

A solution of hydrochloric acid contains 3.2 g of hydrogen chloride in 50 cm³ Calculate the concentration of hydrogen chloride in g per dm³

This question is about acids and bases.

Which ion is found in all acids? Tick one box.

Zinc nitrate can be produced by reacting an acid and a metal oxide. Name the acid and the metal oxide used to produce zinc nitrate.

In an equation, zinc nitrate is written as Zn(NO₃)₂(aq). What does (aq) mean? Tick one box.

The pH of a solution is 8 Some hydrochloric acid is added to the solution. Suggest the pH of the solution after mixing.

Table 2 shows the solubility of three solids in water at room temperature.

A teacher labelled these three solids A, B and C. She gave a student the information shown in Table 3

Describe a method that could be used to identify each of the three solids A, B and C. You must use an indicator in the method. Use information in Table 2 and Table 3

A student plans a method to prepare pure crystals of copper sulfate. The student’s method is:

1. Add one spatula of calcium carbonate to dilute hydrochloric acid in a beaker.

2. When the fizzing stops, heat the solution with a Bunsen burner until all the liquid is gone.

The method contains several errors and does not produce copper sulfate crystals. Explain the improvements the student should make to the method so that pure crystals of copper sulfate are produced.

This question is about iron. Iron reacts with dilute hydrochloric acid to produce iron chloride solution and one other product.

Name the other product.

Suggest how any unreacted iron can be separated from the mixture.

Magnesium reacts with iron chloride solution.

0.120 g of magnesium reacts with excess iron chloride solution. Relative atomic masses (A_r): Mg = 24 Fe = 56 Calculate the mass of iron produced, in mg

Explain which species is reduced in the reaction between magnesium and iron chloride.

Your answer should include the half equation for the reduction.