Physical Properties of the Group 17 Elements (Cambridge (CIE) AS Chemistry)

Chlorine is a greenish-yellow gas, bromine is a dark red liquid, and iodine is a dark grey solid.

State and explain the property which most directly causes these differences in volatility.

Explain why Cl₂ rather than Br₂ would react more vigorously with a solution of I^-.

Astatine, At, is the rarest naturally occurring element in the Earth’s crust. Before it was discovered in 1940 scientists could only predict its existence and properties.

Suggest the basis for these predictions.

State and explain the trend in the boiling points of the halogens from fluorine to iodine.

trend 

explanation 

The bond enthalpies of the halogens generally decrease down the group as shown in Table 3.1. 

Table 3.1 

State and explain the deviation in this trend.

deviation

explanation

Chlorine is a strong oxidising agent.

Write the simplest ionic equation for the reaction between chlorine and aqueous sodium iodide. State what is observed when this reaction occurs.

equation

observation