Group 1: the alkali metals

A small piece of lithium is added to a trough of water.

State two observations made when lithium reacts with water.

What are the products of the reaction?

After the reaction is complete, a few drops of universal indicator are added to the solution in the trough.

Explain the colour and pH of the solution in the trough.

Give the formula of the ion responsible for this pH.

Lithium ions can be identified using a flame test.

What flame colour indicates the presence of lithium ions?

This question is about Group 1 metals.

A teacher adds a small piece of lithium metal to a trough containing water.

Complete the equation for the reaction between lithium and water by adding the state symbols.

Give two observations made when the lithium is added to the water.

The reaction produces 375 cm³ of hydrogen gas at room temperature and pressure (rtp).

Show, by calculation, that the mass of lithium added is between 0.20 g and 0.30 g.

[1 mol of gas has a volume of 24 000 cm³ at rtp]

[for lithium, A_r = 7]

Potassium is more reactive than lithium.

The diagram shows the electronic structure of an atom of lithium and an atom of potassium.

Give one observation that is different when a small piece of potassium, instead of lithium, is added to water.

Explain why potassium is more reactive than lithium.

Refer to the electronic structure of lithium and of potassium in your answer.

A teacher adds a small piece of lithium to water and collects the gas produced.

Give two observations when lithium is added to water.

The teacher adds a few drops of universal indicator to the solution at the end of the reaction.

Explain the final colour of the universal indicator.

This is the equation for the reaction between lithium and water.

The teacher collects 550 cm³ of hydrogen at rtp.

Calculate the mass, in grams, of lithium that the teacher added to the water.

[one mole of gas at rtp has a volume of 24 000 cm³]

[for lithium, A_r = 7]

[for carbon A_r = 12 for hydrogen, A_r = 1 for oxygen A_r = 16]

The teacher then adds a small piece of potassium to water.

Give one observation seen with potassium that is not seen with lithium.

Explain why potassium is more reactive than lithium.

Refer to atomic structure in your answer.

This question is about the alkali metals.

A teacher demonstrates the reaction between sodium and water.

The teacher fills a trough with water and then adds a piece of sodium.

The sodium reacts with the water, forming bubbles of hydrogen gas and a colourless solution.

State two other observations that would be made.

Give a test to show that, at the end of the reaction, the solution contains sodium ions.

Lithium, sodium and potassium react in a similar way when added to water.

State, with reference to the electronic configurations of atoms, why these elements have similar reactions.

The table shows the atomic radius of a lithium atom, a sodium atom and a potassium atom.

Deduce the relationship between the atomic radius and the reactivity of the metals.

Use the Periodic Table to answer these questions.

Give the name of the element with atomic number 16

Give the name of the element with relative atomic mass 9

Give the name of the element in Group 3 and Period 2

Give the electronic configuration of an atom of silicon.

Explain, in terms of electron configuration, why sodium is more reactive than lithium.

This question is about lithium and some of its compounds.

A small piece of lithium is added to a trough containing water.

The lithium floats on the surface of the water and a vigorous reaction occurs.

Give two other observations when lithium reacts with water.

A few drops of methyl orange are added to the solution in the trough.

Explain the final colour of the solution.

An unlabelled bottle containing a white powder is found in a laboratory.

Describe tests to show that the white powder in the bottle is lithium carbonate.

Lithium carbonate has ionic bonding.

State what is meant by the term ionic bonding.

Describe the forces of attraction in metallic bonding.

When a small piece of potassium is added to water, bubbles of hydrogen gas are observed.

Give the test for hydrogen gas.

Give two other observations that would be made.

Explain why lithium is less reactive than potassium.

Refer to atomic structure in your answer.

This is the equation for the reaction between sodium and water.

A mass of 0.750 g of sodium is reacted with an excess of water.

Calculate the volume of hydrogen gas produced, in cm³, at room temperature.

[molar volume of hydrogen at rtp = 24 000 cm³]

[for Na,A_r = 23]

Give your answer to three significant figures.

This is the equation for the reaction between sodium hydroxide and sulfuric acid.

A volume of 25.0 cm³ of sodium hydroxide solution is completely neutralised by 16.3 cm³ of 0.0500 mol / dm³ sulfuric acid.

Calculate the concentration of the sodium hydroxide solution in mol / dm³.

concentration =_........ mol / dm

Iron metal was discovered several thousand years ago. Iron is produced industrially from iron(III) oxide by extraction using carbon.

Sodium is a metal in Group 1 of the Periodic Table. Sodium was discovered by Sir Humphrey Davy in 1807. It is produced industrially by the electrolysis of sodium chloride.

Explain, using the reactivity series, why carbon can be used to extract iron from iron(III) oxide.

Suggest why sodium was not discovered until 1807.

The diagram shows a simplified version of the Downs cell, which can be used to produce sodium industrially. The electrolyte is molten sodium chloride.

Explain why the molten electrolyte conducts electricity.

What is the formula of the cation in the electrolyte?

During the production of sodium, small explosions can be heard.

Explain why using sodium chloride that is not completely dry could cause these small explosions.

Give ionic half-equations for the reactions at the anode and cathode.

Explain why the reactivity of metals in Group 1 increases from lithium to potassium.

The diagram shows the positions of some elements in part of the Periodic Table.

Na A l S C l

K Xe

Give the symbol of a metal from the diagram.

Give the symbol of an element from the diagram that forms an acidic oxide.

Give a similarity in the electron configurations of A l and I n.

Explain which element in the diagram is unreactive.

A teacher adds a small piece of sodium to a glass trough containing water and universal indicator.

The universal indicator changes colour.

The equation for the reaction is

Explain the final colour of the universal indicator.

The teacher repeats the experiment with potassium instead of sodium.

Give one similarity and one difference observed with potassium.

similarity

difference

The reaction with sodium produces 0.036 g of hydrogen gas.

One mole of hydrogen gas contains 6.010²³ molecules.

Calculate the number of molecules of hydrogen gas produced in the reaction with sodium.

Give your answer to two significant figures.

This question is about the reactions of Group 1 metals with water.

A teacher adds a piece of sodium to some water containing universal indicator.

The equation for this reaction is

The sodium floats on the surface of the water and the universal indicator changes colour because an alkaline solution is formed.

Give two other observations.

Give the final colour of the universal indicator.

The diagram represents an atom of lithium and an atom of sodium.

Give a reason why lithium and sodium have similar reactions with water.

Explain why lithium is less reactive than sodium.

The teacher adds 0.150 g of lithium to an excess of water and collects the hydrogen gas produced.

The equation for the reaction is

The teacher collects 254 cm³ of hydrogen gas at room temperature and pressure (rtp).

Show by calculation that 1 mol of hydrogen gas has a volume of approximately 24 000 cm³ at rtp.

Use the Periodic Table to help you answer this question.

Identify the element with atomic number 7

Identify a solid non‑metallic element in Period 3

Name an element in Group 7 that is a liquid at room temperature.

State the relative atomic mass of the element that is in Group 4 and Period 4

Which row shows the most reactive element in Group 1 and Group 7?

Lithium, sodium and potassium are the first three elements in Group 1 of the Periodic Table.

Suggest why these three elements are all stored in paraffin oil.

Caesium, Cs, is below potassium in Group 1.

Give a similarity and a difference between the reactions of potassium with water and caesium with water.

Give the chemical equation for the reaction between caesium and water.

A student investigates the temperature change in the reaction between dilute acids and solutions of Group 1 hydroxides.

He uses this apparatus.

This is the student’s method.

measure the temperature of 50 cm³ of hydrochloric acid

pour the acid into a polystyrene cup

add 50 cm³ of sodium hydroxide solution to the acid

measure the maximum temperature of the mixture

Suggest what could be added to the apparatus to improve the experiment.

Explain a change to the method that would improve the accuracy of the experiment.

These are the student’s results.

temperature of hydrochloric acid = 19.9 °C

maximum temperature of mixture = 26.5 °C

Calculate the energy change, Q, in joules for this reaction.

[mass of 1.0 cm³ of mixture = 1.0 g]

[for the mixture, c = 4.2 J/g/°C]

In the student’s reaction between hydrochloric acid and sodium hydroxide, 0.050 mol of water forms.

Calculate the molar enthalpy change, Δ H, in kJ/mol for this reaction.

ΔH =_........ kJ/mol

This question is about sodium and potassium.

A trough is filled with water and a few drops of phenolphthalein indicator are added.

A small piece of sodium is dropped into the water. One of the products of the reaction is an alkali.

Complete the chemical equation for the reaction of sodium with water.

_____Na(_........ ) + ______H₂O(l) _____NaOH(_........ ) + H₂(g)

Identify the ion that causes the solution to become alkaline.

Give three observations that would be made when sodium reacts with water.

Explain why potassium is more reactive than sodium.

Refer to the electronic configurations of the atoms in your answer.

This question is about chemical elements.

Use the Periodic Table to help you answer this question.

Identify the element with atomic number 5

Give the symbol of a metallic element in Period 3

Identify the element whose atoms contain 14 protons.

Identify the element whose atoms have the electronic configuration 2.5

Give the name of the compound formed between oxygen and the element with atomic number 13

The position of an element in the Periodic Table can be used to predict its properties.

Which group contains elements that are all unreactive?

Which of these is the least reactive element in Group 1?

This question is about some of the alkali metals and their compounds.

When a teacher drops a small piece of sodium into a trough of cold water, she observes bubbles of gas.

Give two other observations that would be made when sodium reacts with cold water.

Lithium reacts with fluorine to form the compound lithium fluoride.

Give a chemical equation for this reaction.

Give a test to show that lithium fluoride contains lithium ions.

Draw diagrams to show the arrangement of the electrons in a lithium ion and in a fluoride ion.

Include the charge on each ion.

lithium ion
fluoride ion

The table shows the electronic configurations of sodium and potassium.

Explain, in terms of their electronic configurations, why potassium is more reactive than sodium.

This question is about Group 1 metals and their reactions.

When lithium is added to water, bubbles of hydrogen gas are observed.

Give two other observations that could be made.

Give the test for hydrogen gas.

Give one observation that would be different if potassium is used instead of lithium.

The diagram represents an atom of lithium and an atom of potassium.

Explain why potassium is more reactive than lithium.

The equation for the reaction between lithium and water is

A mass of 0.500 g of lithium reacts with an excess of water.

Calculate the volume, in cm³, of hydrogen gas produced at rtp.

[molar volume of a gas at rtp = 24 000 cm³]

Give your answer to three significant figures.

In a reaction between lithium and water, 150 cm³ of lithium hydroxide solution is formed.

The lithium hydroxide solution is then completely neutralised by 24.85 cm³ of 0.100 mol/dm³ sulfuric acid.

The equation for the neutralisation is

Calculate the concentration, in mol/dm³, of the lithium hydroxide solution.

concentration =_........ mol/dm