Group 7 Flashcards
Describe the physical properties of the halogens at room temperature
- Fluorine is a very pale yellow gas
- Chlorine is a greenish gas
- Bromine is an orange/ brown liquid which vaporises easily into an orange gas
- Iodine is a black solid which vapoises on heating to a purple gas
- All have swimming pool smell
Why does fluorine have some different properties to the other halogens
- F-F bond is weak
- Due to fluorine atoms being very small so the non-bonding pairs of electrons on the outer shells are held so close together they begin to repel
Describe the structure and bonding in the halogens and why the melting points of halogens increase down the group
- Covalent structure: shared pair of electrons
- Going down, more shells, so more shielding
- Nuclear attraction gets weaker so requires more energy to gain an electron
Give the sodium-containing product for the reaction of Sodium Bromide with H2SO4
SO2
Give the 3 sodium-containing products for the reaction of Sodium Iodide with H2SO4
- SO2
- S
- H2S
For the redox reaction of sodium bromide with H2SO4 give:
- the full redox equation
- the 2 observations and which product causes each
- the role of the Br- ion
H2SO4 + 2Br- + 2H+ –> Br2 + SO2 + 2H2O
- Orange solution: Br2
- Acidic gas: SO2
- Br- is the reducing agent
For the redox reaction of sodium iodide with H2SO4 to form SO2 give:
- the full redox equation
- the two observations and which product causes them
- the role of the I- ion
H2SO4 + 2H+ + 2I- –> I2 + SO2 + 2H2O
- Black solid: I2
- Acidic gas: SO2
- I- is the reducing agent
For the redox reaction of sodium iodide with H2SO4 to form S give:
- the full redox equation
- the two observations and which product causes them
- the role of the I- ion
H2SO4 + 6I- + 6H+ –> S +3I2 + 4H2O
- Yellow solid: S
- Black solid: I2
- I- is the reducing agent
For the redox reaction of sodium iodide with H2SO4 to form H2S give:
- the full redox equation
- the two observations and which product causes them
- the role of the I- ion
H2SO4 + 8I- + 8H+ –> H2S + 4I2 + 4H2O
- Bad odour: H2S
- Black solid: 4I-
- I- is the reducing agent
For the acid-base reaction of sodium chloride with H2SO4 give:
- The ionic equation needed to produce the observation
- The role of the Cl- ion
H+ + Cl- –> HCl
- Cl- is the base
For the displacement reaction for chloride with sodium bromide give:
- The full equation
- The observation and which product causes it
Cl2 + 2Br- –> Br2 + 2Cl
- Orange solution: Br2
For the displacement reaction for chloride with sodium iodide give:
- The full equation
- The observation and which product causes it
Cl2 + 2I- –> 2Cl- + I2
- Black solid: I2
For the displacement reaction for bromine with sodium iodide give:
- The full equation
- The observation and which product causes it
Br2 + 2I- –> I2 + 2Br-
- Black solid: I2
Give the equation for the formation of a white precipitate when AgNO3 is added to a soltuion containing a halide
Ag+ + Cl- –> AgCl
Give the equation for the formation of a cream precipitate when AgNO3 is added to a soltuion containing a halide
Ag+ + Br- –> AgBr