The halogens
Cards (21)
- Properties of halogens
- Low melting and boiling points
- Exist as diatomic molecules
- The trend in reducing ability of the halides down the group increases, with Cl- being the weakest and I- being the strongest, as I- has the most occupied electron shell, making outer electrons further from the nucleus and having the weakest force of attraction between outer electrons and positive charge of the nucleus, making it the easiest to be oxidised and lose electrons, hence the best reducing agent
- The trend in reactivity down Group 7 decreases because the atomic radius increases, electron shielding increases, and the ability to gain an electron and form 1- ions decreases
- Group 7 elements are referred to as halogens
- The trend in boiling point down Group 7 increases because the size of the atom increases as more occupied electron shells, leading to stronger London forces of attraction between molecules which require more energy to break
- The trend in oxidising ability down the group decreases, with Cl being the strongest and I being the weakest, as Cl has the fewest occupied electron shells and the greatest force of attraction between outer electrons and nucleus, making it the easiest to gain electrons and be reduced, hence the best oxidising agent
- When a more reactive halogen displaces a less reactive halide, the reaction is called a displacement reaction
- What is the colour of chlorine in cyclohexane?
- What is the colour of iodine in cyclohexane?
- What is the colour of bromine in water?
- Out of the 3 halides Cl-, Br- & I-, which one of these can be oxidised by bromine?
- When a more reactive halogen displaces a less reactive halide, what is the reaction called?
- Write the equation for chlorine oxidising bromide ions
- What is the colour of chlorine in water?
- What is the colour of iodine in water?
- Write the equation for Cl₂ oxidising 2I-
- Out of the 3 halides Cl-, Br- & I-, which one of these can be oxidised by chlorine?
- What is the colour of bromine in cyclohexane?
- Does not oxidise Cl- or Br-
- Disproportionation; chlorine is both oxidised and reduced
- Out of the 3 halides Cl-, Br-, & I-, I- ions can be oxidised by bromine