Group 7 Practice Questions

The table gives some information about three halogens at room temperature.

halogen	colour at room temperature	state at room temperature
chlorine	....................	gas
bromine	orange-brown	....................
iodine	....................	....................

Complete the table.

Fluorine is the element above chlorine in group 7.

Predict the state of fluorine at room temperature and give a reason for your prediction.

Complete the word equation for the reaction of hydrogen with iodine.

hydrogen + iodine $\rightarrow$ ....................

Hydrogen iodide dissolves in water.

State the name of the solution that is formed.

A piece of blue litmus paper is dipped into this solution.

State what is seen.

Describe what is seen when the bromine water is added to the potassium iodide solution and the mixture is shaken.

Complete the word equation for the reaction that takes place.

bromine + potassium iodide $\rightarrow$ .................... + ....................

Describe the trend in boiling point of the halogens going down group 7.

Predict the boiling point of fluorine.

Give a reason for your prediction.

Use the data in the table to explain why bromine is a liquid at a room temperature of 20 °C.

A piece of sodium is heated and lowered into a gas jar of chlorine. It burns with a bright yellow flame to form a white solid.

Write the balanced equation for this reaction.

Hot iron wool reacts with chlorine gas to form iron(III) chloride.

Write the balanced equation for this reaction.

Calcium also reacts with halogens.

Predict the name and the formula of the compound formed when calcium reacts with bromine.

Complete the table by writing 'reaction' or 'no reaction' in the two empty boxes.

Use the results to put chlorine, bromine and iodine in order of reactivity, starting with the most reactive.

Astatine is below iodine in group 7.

Predict what would be seen if a solution of astatine was added to potassium iodide solution.

Explain your answer.

Write the ionic equation for this reaction.

Explain, in terms of electrons, why the iodide ions are oxidised in this reaction.

State the name of the substance that is reduced in this reaction.

State the colour and the state of chlorine at room temperature.

Describe how the student could show that the gas in the gas jar is chlorine, and state the result of the test.

Predict the name and the formula of the compound formed when lithium reacts with astatine.

Astatine reacts with hydrogen to form hydrogen astatide.

Predict the pH of the solution formed when hydrogen astatide dissolves in water.

Give a reason for your prediction.

A solution of astatine is added to potassium bromide solution.

Predict whether a reaction occurs. Give a reason for your prediction.

Write the half equation for the formation of chloride ions from chlorine.

Write the half equation for the formation of iodine from iodide ions.

Explain why this reaction is a redox reaction.

Use the diagram to explain why chlorine forms ions with a charge of $1-$.

Chlorine is more reactive than iodine.

Explain, in terms of electronic configuration, why the reactivity of the halogens decreases going down group 7.

Write the balanced equation for the reaction of chlorine with sodium bromide.

Explain the observations shown in the table.