This question is about elements in Group 7 of the Periodic Table.
The table shows some properties of Group 7 elements.
| Element | Molecular formula | Melting point (∘C^\circ\text{C}∘C) | Boiling point (∘C^\circ\text{C}∘C) | Order of reactivity |
|---|---|---|---|---|
| Fluorine | F2\text{F}_2F2 | −220-220−220 | −188-188−188 | most reactive ↓\downarrow↓ |
| Chlorine | Cl2\text{Cl}_2Cl2 | −101-101−101 | .................... | ↓\downarrow↓ |
| Bromine | Br2\text{Br}_2Br2 | .................... | 595959 | ↓\downarrow↓ |
| Iodine | I2\text{I}_2I2 | 114114114 | 184184184 | ↓\downarrow↓ |
| Astatine | At2\text{At}_2At2 | 302302302 | 337337337 | least reactive |
Complete the table by estimating the missing boiling point of chlorine and the melting point of bromine. Use ideas about trends down Group 7.
Chlorine reacts with sodium bromide, NaBr\text{NaBr}NaBr, in a displacement reaction. Write the balanced symbol equation for this reaction.
Explain, in terms of the arrangement of electrons, the decrease in reactivity from fluorine to astatine.
Sodium reacts with chlorine to form sodium chloride according to the equation:
2Na+Cl2→2NaCl 2\text{Na} + \text{Cl}_2 \rightarrow 2\text{NaCl} 2Na+Cl2→2NaClCalculate the mass of sodium chloride that can be made from 3.45 g3.45\text{ g}3.45 g of sodium. Give your answer to 3 significant figures.
(The relative atomic mass, ArA_rAr, of Cl\text{Cl}Cl is 35.535.535.5 and of Na\text{Na}Na is 23.023.023.0).
41 exam-style questions on OCR GCSE Chemistry Predicting chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.