The table gives information about the first three elements in Group 7 of the Periodic Table.
| Element | Atomic number | Relative atomic mass | Electronic configuration | Boiling point in ∘C^\circ\text{C}∘C |
|---|---|---|---|---|
| fluorine | 9 | 19 | 2.7 | -188 |
| chlorine | 17 | 35.5 | 2.8.7 | -34 |
| bromine | 35 | 80 | 2.8.18.7 | 59 |
Which information shows that the elements have similar chemical properties? Give a reason for your choice.
The elements in Group 7 show a clear trend (regular pattern) in some of their physical properties. Identify the physical property that shows a clear trend in the table.
The elements also show a clear trend in their chemical properties, such as their reaction with hydrogen.
When chlorine gas is mixed with hydrogen gas and exposed to UV light, it reacts explosively to form hydrogen chloride gas.
Describe a test to show that the gas given off (hydrogen chloride) is acidic.
Complete the equation for the reaction by inserting the state symbols.
H2(…… )+Cl2(…… )→2HCl(…… ) \text{H}_2(\dots\dots) + \text{Cl}_2(\dots\dots) \rightarrow 2\text{HCl}(\dots\dots) H2(……)+Cl2(……)→2HCl(……)soul
State and explain the effect that a solution of this gas in water has on blue litmus paper.
State two similarities and two differences between the reactions of fluorine and chlorine with hydrogen.
When sodium burns in chlorine gas, it forms sodium chloride (NaCl\text{NaCl}NaCl). Write a chemical equation for this reaction.
When iron reacts with chlorine gas, iron(III) chloride (FeCl3\text{FeCl}_3FeCl3) is formed. Balance the equation to show the formation of iron(III) chloride:
……Fe+……Cl2→……FeCl3 \dots\dots\text{Fe} + \dots\dots\text{Cl}_2 \rightarrow \dots\dots\text{FeCl}_3 ……Fe+……Cl2→……FeCl3
