Chemical bonds

Lithium reacts with chlorine to produce lithium chloride.

Figure 10 shows models of chlorine and of lithium chloride.

Draw one line from each substance to the type of bonding in the substance.

Lithium chloride can also be produced by reacting lithium carbonate with an acid.

Which acid reacts with lithium carbonate to produce lithium chloride?

Tick () one box.

Hydrochloric acid

Nitric acid

Sulfuric acid

What type of substance is lithium chloride?

Tick () one box.

Acid

Alkali

Salt

Figure 11 shows the electrolysis of lithium chloride solution.

Lithium chloride solution contains Li⁺ ions and Cl⁻ ions.

Chloride ions move to the positive electrode to produce chlorine.

Explain why chloride ions move to the positive electrode.

Hydrogen gas and chlorine gas are produced during the electrolysis of lithium chloride solution.

Draw one line from each gas to the result of the test for that gas.

Why is hydrogen gas produced at the negative electrode?

Tick () one box.

Hydrogen is less reactive than lithium.

Hydrogen has the same reactivity as lithium.

Hydrogen is more reactive than lithium.

Hydrogen reacts with chlorine to produce hydrogen chloride. A hydrogen atom has 1 electron in the outer shell.

A chlorine atom has 7 electrons in the outer shell.

Complete the dot and cross diagram for a hydrogen chloride molecule.

Use the symbols O and X to represent electrons.

Alkanes are used as fuels.

Butane is an alkane.

Figure 4 shows butane being used to heat a copper kettle.

The use of butane as a fuel involves a combustion reaction.

What gas in the air does butane react with during combustion?

Why is copper a suitable material for a kettle?

Tick () one box.

Copper can be shaped.

Copper has a low melting point.

Copper reacts with water.

Figure 5 represents a butane molecule.

What is the type of bonding in a butane molecule?

Use Figure 5.

Tick () one box.

Covalent

Ionic

Metallic

What type of structure does butane have?

Use Figure 5.

Tick () one box.

Giant structure

Polymer

Small molecule

Table 2 shows the melting points and boiling points of three alkanes.

Which alkane is a liquid at − 185 °C?

Tick () one box.

Ethane

Propane

Butane

This question is about the elements magnesium, oxygen and lithium.

What is the type of bonding in magnesium?

Tick (✓) one box.

Covalent

Ionic

Metallic

What is the type of bonding in oxygen?

Tick (✓) one box.

Covalent

Ionic

Metallic

Magnesium atoms react with oxygen atoms to produce magnesium oxide.

Magnesium oxide contains magnesium ions and oxide ions.

Figure 8 shows the electronic structure of the atoms and the ions.

Only the outer shell electrons are shown.

Describe what happens when a magnesium atom reacts with an oxygen atom to produce a magnesium ion and an oxide ion.

Answer in terms of electrons.

Lithium is an element in Group 1 of the periodic table.

Figure 9 shows a piece of lithium stored in oil.

Suggest why lithium is stored in oil.

A teacher reacted 0.5 g of lithium with oxygen.

The teacher measured the mass of lithium oxide produced.

The teacher repeated the experiment with different masses of lithium.

Table 2 shows the results.

Describe the relationship between the mass of lithium reacted and the mass of lithium oxide produced.

Complete Figure 10.

You should:

label the x-axis

plot the data from Table 2

draw a line of best fit.

The teacher did the experiment four times using 0.25 g of lithium.

Table 3 shows the results.

Calculate mean value X in Table 3.

Hydrogen reacts with oxygen to produce water.

Figure 6 represents the equation for the reaction.

Figure 6

Table 1 shows bond energies.

Calculate the energy released during bond formation in the reaction.

Use Figure 6 and Table 1.

Energy released = __________________ kJ/mol

In the reaction to produce water, the energy needed to break bonds is less than the energy released when bonds are formed.

Which reaction profile represents this reaction?

Tick (✓) one box.

Complete the dot and cross diagram for a water molecule.

Explain why hydrogen gas (H₂) consists of molecules rather than single atoms.

This question is about bonds.

Compare the bonding in hydrogen gas (H₂) with the bonding in copper metal.

Hydrogen reacts with oxygen to produce water.

The equation for the reaction is:

The energy released in forming new bonds is 486 kJ/mol greater than the energy needed to break the existing bonds.

Table 2 shows some bond energy values.

Y is the bond energy of a H‒H bond.

Calculate Y.

A teacher extracted copper from copper oxide.

This is the method used.

1. Mix 1.30 g of zinc and 1.59 g of copper oxide.

2. Heat the mixture strongly.

3. When the mixture starts to glow, stop heating.

4. Let the glow spread through the mixture.

5. Leave the mixture to cool.

This reaction is exothermic.

Which part of the method shows the reaction is exothermic?

Tick one box.

The equation for the reaction between zinc and copper oxide is:

1.30 g of zinc fully reacted with 1.59 g of copper oxide to produce 1.62 g of zinc oxide.

What mass of copper was produced?

What is the physical state of zinc oxide in the reaction?

Tick one box.

Which substance has been oxidised in the reaction?

Tick one box.

What type of reaction takes place when zinc reacts with copper oxide?

Tick one box.

Copper is a metal.

Which structure represents the arrangement of atoms in pure copper?

Tick one box.

Copper is used in electrical wiring.

Give one reason why.

In the UK, 40% of the copper we use is recycled copper.

The other 60% is copper obtained by mining.

What is the simplest ratio of recycled copper to copper obtained by mining?

Tick one box.

What are two advantages of recycling copper?

Tick two boxes.

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

This question is about hydrogen chloride.

A hydrogen atom contains 1 electron and a chlorine atom contains 17 electrons.

Complete Figure 7 to show a dot and cross diagram for a hydrogen chloride molecule.

Show the outer electrons only.

Hydrogen gas (H₂) reacts with chlorine gas to produce hydrogen chloride.

Complete the balanced chemical equation for the reaction between hydrogen and chlorine.

Figure 8 shows the reaction profile diagram for the reaction between hydrogen and chlorine.

What do A and B represent on Figure 8 ?

How does the reaction profile diagram show that the reaction is exothermic?

Hydrogen chloride gas dissolves in water to form hydrochloric acid.

Hydrochloric acid contains hydrogen ions and chloride ions.

Explain why hydrogen chloride gas does not conduct electricity but hydrochloric acid is able to conduct electricity.