Relative formula mass

This question is about acids and alkalis.

Universal indicator is used to measure the pH of solutions.

Figure 16 shows the colours of universal indicator at different pH values.

A student added universal indicator to nitric acid in a beaker.

The student added drops of potassium hydroxide solution to the nitric acid until pH 7 was reached.

The student could not be sure that the pH of the mixture was 7

Give one reason why.

Use Figure 16.

Name a piece of equipment that could be used to give a more accurate measurement of pH.

Name the type of reaction when potassium hydroxide solution reacts with nitric acid.

The formula of nitric acid is HNO₃

Calculate the relative formula mass (M_r) of nitric acid.

Relative atomic masses (A_r): H = 1 N = 14 O = 16

Potassium hydroxide is an alkali.

Which ion do all alkalis contain?

Tick () one box.

H⁺ K⁺ O²⁻ OH⁻

The concentration of the solution of potassium hydroxide was 5.6 g/dm³.

Calculate the mass of potassium hydroxide in 5 cm³ of the solution.

1 dm³ = 1000 cm³

This question is about acids and alkalis.

Universal indicator is used to measure the pH of solutions.

Figure 3 shows the colours of universal indicator at different pH values.

A student added universal indicator to nitric acid in a beaker.

The student added drops of potassium hydroxide solution to the nitric acid until pH 7 was reached.

The student could not be sure that the pH of the mixture was 7

Give one reason why.

Use Figure 3.

Name a piece of equipment that could be used to give a more accurate measurement of pH.

Name the type of reaction when potassium hydroxide solution reacts with nitric acid.

The formula of nitric acid is HNO₃

Calculate the relative formula mass (M_r) of nitric acid.

Relative atomic masses (A_r): H = 1 N = 14 O = 16

Potassium hydroxide is an alkali.

Which ion do all alkalis contain?

Tick () one box.

H⁺ K⁺ O²⁻ OH⁻

The concentration of the solution of potassium hydroxide was 5.6 g/dm³.

Calculate the mass of potassium hydroxide in 5 cm³ of the solution.

1 dm³ = 1000 cm³

This question is about hydrocarbons.

Name the two elements in a hydrocarbon.

Which two of the following substances are hydrocarbons?

Tick (✓) two boxes.

Ammonia

Ethene

Graphite

Methane

Steam

C₆H₁₄ is a hydrocarbon.

C₆H₁₄ can be broken down into smaller molecules.

Complete the equation for the breakdown of C₆H₁₄ into smaller molecules.

What is the name of the process t hat breaks d own C₆H₁₄ into smaller molecules?

Tick (✓) one box.

Cracking

Distillation

Neutralisation

How does the boiling point of C₆H₁₄ compare with the boiling point of C₄H₁₀?

Give one reason for your answer.

Tick (✓) one box.

C₆H₁₄ has a lower boiling point.

C₆H₁₄ and C₄H₁₀ have the same boiling point.

C₆H₁₄ has a higher boiling point.

The complete combustion of C₆H₁₄ produces water and one other product.

Name the other product of the complete combustion of C₆H₁₄

Do not refer to water in your answer.

The formula of water is H₂O

Calculate the relative formula mass (M_r) of water.

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

A student electrolysed copper sulfate solution using inert electrodes.

Figure 8 shows the apparatus used.

Copper was produced at the negative electrode.

Oxygen was produced at the positive electrode.

Copper sulfate solution contains copper ions and hydrogen ions.

Why is copper produced instead of hydrogen during the electrolysis of copper sulfate solution?

Tick (✓) one box.

Copper is less reactive than hydrogen.

Copper has the same reactivity as hydrogen.

Copper is more reactive than hydrogen.

The student measured how the mass of copper produced varied with time.

Table 1 shows the results.

What conclusion can be made about how the mass of copper produced varied with time?

Use Table 1.

Predict the time taken to produce 0.20 g of copper.

Use Table 1.

0.5 dm³ of a solution of copper sulfate contains 3.2 g of copper sulfate.

Calculate the concentration of the solution of copper sulfate.

Use the equation:

Choose the unit from the box.

Copper sulfate has the formula CuSO₄

Calculate the percentage (%) by mass of copper in CuSO₄

Give your answer to 3 significant figures.

Relative atomic mass (A_r): Cu = 63.5

Relative formula mass (M_r): CuSO₄ = 159.5

This question is about acids and salts.

Nitric acid is a strong acid.

A solution of nitric acid can be dilute.

Explain how nitric acid can be both strong and dilute.

The pH value of a solution of nitric acid increases by 1.

How does the hydrogen ion concentration of the solution change?

Tick (✓) one box.

Decreases by a factor of 10

Decreases by a factor of 100

Increases by a factor of 10

Increases by a factor of 100

Question 8 continues in the next page

A student reacted nitric acid with excess calcium carbonate.

The word equation for the reaction is:

calcium carbonate + nitric acid calcium nitrate + water + carbon dioxide

This is the method used.

1. Measure 100 cm³ of nitric acid into a beaker.

2. Add calcium carbonate powder to the nitric acid.

3. Stir the mixture.

4. Repeat steps 2 and 3 until the calcium carbonate is in excess.

5. Filter the mixture.

Describe the additional steps that should be included in the method to determine the mass of calcium carbonate that reacted.

The formula of nitric acid is HNO₃

Which expression gives the percentage (%) by mass of oxygen in HNO₃?

Relative atomic mass (A_r): O = 16

Relative formula mass (M_r): HNO₃ = 63

Tick (✓) one box.

What is the formula of calcium nitrate?

Use the periodic table.

Tick (✓) one box.

CaNO₃

Ca(NO₃)₂

Ca₂NO₃

Ca₂(NO₃)₃

Question 8 continues in the next page

Magnesium chloride is a salt.

Calculate the number of magnesium ions in 47.5 g of magnesium chloride (MgCl₂).

Relative atomic masses (A_r): Mg = 24 Cl = 35.5

Avogadro constant = 6.02 × 10²³ per mole

This question is about structure and bonding.

Why can metals be shaped?

Tick (✓) one box.

Different-sized atoms distort the structure.

Layers of atoms slide over each other.

Metallic bonds are weak.

Metals have low melting points.

Explain how metals conduct electricity.

You should answer in terms of electrons.

Figure 9 represents the structure of diamond and of sodium chloride.

Compare the structure and bonding of diamond with the structure and bonding of sodium chloride.

Ethene (C₂H₄) is a small molecule.

Calculate the relative formula mass (M_r) of ethene.

Relative atomic masses (A_r): C = 12 H = 1

Ethene molecules join together to form long-chain poly(ethene) molecules.

Explain why poly(ethene) has a higher melting point than ethene.

You should refer to the:

This question is about structure and bonding.

Why can metals be shaped?

Tick (✓) one box.

Different-sized atoms distort the structure.

Layers of atoms slide over each other.

Metallic bonds are weak.

Metals have low melting points.

Explain how metals conduct electricity.

You should answer in terms of electrons.

Figure 1 represents the structure of diamond and of sodium chloride.

Compare the structure and bonding of diamond with the structure and bonding of sodium chloride.

Ethene (C₂H₄) is a small molecule.

Calculate the relative formula mass (M_r) of ethene.

Relative atomic masses (A_r): C = 12 H = 1

Ethene molecules join together to form long-chain poly(ethene) molecules.

Explain why poly(ethene) has a higher melting point than ethene.

You should refer to the:

This question is about chemical quantities.

0.40 dm³ of a solution contains 48.4 g of solute.

Calculate the concentration of the solution.

Give the unit.

Calculate the number of carbon dioxide molecules in 3.00 moles of carbon dioxide.

The Avogadro constant = 6.02 × 10²³ per mole.

Give your answer to 3 significant figures.

Metal M forms a metal oxide with the formula M₂O₃

The relative formula mass of the metal oxide is 152.

Determine the identity of metal M.

Relative atomic mass (A_r): O = 16

This question is about ammonium chloride.

Ammonium chloride (NH₄Cl) decomposes to produce ammonia (NH₃) and hydrogen chloride (HC l).

The reaction is reversible.

The equation for the reaction is:

What is the state of hydrogen chloride in this reaction?

Tick (✓) one box.

Aqueous

Gas

Liquid

Solid

How does the equation show that the reaction is reversible?

What is the total number of atoms in the formula NH₄C඀?

Tick (✓) one box.

3 4 5 6

When does a reversible reaction reach dynamic equilibrium?

Tick (✓) one box.

When the forward reaction is slower than the reverse reaction.

When the forward reaction and the reverse reaction have the same rate.

When the forward reaction is faster than the reverse reaction.

How must the apparatus for the reaction be designed so that dynamic equilibrium can be reached?

Tick (✓) one box.

So all of the substances can escape.

So none of the substances can escape.

So only ammonia and hydrogen chloride can escape.

Figure 7 represents the electronic structure of a chlorine atom (C ඀).

Which diagram represents the electronic structure of a chloride ion (C ඀ −)?

Tick (✓) one box.

Ammonia has the formula NH₃

Calculate the percentage (%) by mass of nitrogen (N) in NH₃

Relative atomic mass (A_r): N = 14

Relative formula mass (M_r): NH₃ = 17

Give your answer to 2 significant figures.

Figure 8 represents ammonia.

What does ‘ ’ represent in Figure 8?

What type of particle is ammonia?

Tick (✓) one box.

Atom

Ion

Molecule 11

This question is about carbon and carbon compounds.

Carbon forms compounds called alkanes.

Which formula represents an alkane molecule with 8 carbon atoms?

Tick (✓) one box.

C₈H₁₀

C₈H₁₄

C₈H₁₆

C₈H₁₈

Alkanes can be cracked.

Name one method of cracking alkanes.

Explain how cracking alkanes helps to meet the demand for fuels.

Ethene can be produced when alkanes are cracked.

The formula of ethene is C₂H₄

Calculate the simplest whole number ratio by mass of carbon to hydrogen in ethene.

Relative atomic masses (A_r): C = 12 H = 1

Ratio by mass of carbon: hydrogen = ______________: ______________

Carbon exists in different forms.

Which form has each carbon atom bonding with four other carbon atoms?

Tick (✓) one box.

Diamond

Graphene

Graphite

Fullerene molecules are made of carbon atoms.

Give two other features of the structure of fullerene molecules.

A carbon nanotube has:

a length to diameter ratio of 6 900 000: 1

Calculate the length of the carbon nanotube in nm.

Explain why carbon nanotubes are good conductors of electricity.

This question is about the reaction between hydrochloric acid and sodium hydroxide solution.

A student investigated the effect of changing the volume of sodium hydroxide solution on the temperature change during the reaction.

This is the method used.

1. Measure 30 cm³ of hydrochloric acid into a polystyrene cup.

2. Measure the temperature of the hydrochloric acid.

3. Add 5 cm³ of sodium hydroxide solution.

4. Stir the mixture.

5. Measure the highest temperature the mixture reaches.

6. Repeat steps 1 to 5 three more times and calculate the mean temperature change.

7. Repeat steps 1 to 6 with different volumes of sodium hydroxide solution.

What two pieces of equipment should be used in this investigation?

Tick (✓) two boxes.

Balance

Measuring cylinder

Ruler

Stopclock

Thermometer

Table 1 shows the results for one volume of sodium hydroxide solution.

Calculate value X in Table 1.

Which type of error is reduced by repeating the tests and calculating the mean?

Tick (✓) one box.

Random

Systematic

Zero

A different student did the same investigation.

Figure 2 shows the results.

What was the mean temperature change when the volume of sodium hydroxide solution was 15 cm³?

Use Figure 2.

Give one conclusion from the results in Figure 2.

The reaction between hydrochloric acid and sodium hydroxide is exothermic.

Exothermic reactions give out energy.

Which reaction profile shows an exothermic reaction?

Tick (✓) one box.

Calculate the relative formula mass (M_r) of sodium hydroxide (NaOH).

Relative atomic masses (A_r): Na = 23 O = 16 H = 1

This question is about the reaction of metals with sulfuric acid.

The word equation for the reaction of zinc with sulfuric acid is:

zinc + sulfuric acid → zinc sulfate + hydrogen

What type of substance is zinc sulfate?

Tick (✓) one box.

Calculate the relative formula mass (M_r) of zinc sulfate (ZnSO₄).

Relative atomic masses (A_r): Zn = 65 S = 32 O = 16

A student investigated the temperature increase when the same mass of different metals were added to 0.1 M sulphuric acid.

The student used four different metals.

The student did the experiment three times for each metal and calculated the mean temperature increase for each metal.

Table 5 shows the results for nickel.

Calculate value X.

Table 6 shows the mean values for the four metals.

The student plotted the results on a bar chart.

Figure 9 shows the bar chart.

The student made some errors when plotting the bar chart.

Give three errors the student made.

Use Table 6 to place the metals in order of reactivity.

This question is about Group 1 metals.

Figure 1 shows the melting points of Group 1 metals plotted against their atomic number.

Describe the trend shown by the melting points of Group 1 metals as the atomic number increases.

Determine the atomic number and melting point of caesium.

Use Figure 1.

Lithium is a Group 1 metal.

A lithium atom can be shown as.

How many electrons does the outer shell of a lithium atom contain?

Tick one box.

Lithium reacts with oxygen to produce lithium oxide.

Draw one line from each substance to the correct description of the substance.

Balance the equation for the reaction of lithium with oxygen.

What type of bonding is present in lithium oxide?

Tick one box.

Calculate the relative formula mass (M_r) of lithium oxide (Li₂O).

Relative atomic masses (A_r): Li = 7 O = 16