Group 7 Elements Flashcards
What does PEAS stand for?
Protons, Electrons, Attractions and Shielding.
What happens to atomic radius as it goes down the elements?
Atomic Radius Increases
What happens to melting / boiling points as it goes down the elements? Why does this happen?
Melting / Boiling Points increase. This happens because: Atomic radius increases There's more room for London forces. More energy is required to break them Making the melting / boiling point higher.
As it goes down the elements, do the halogens get better or worse at being oxidising agent?
The halogens get worse at being an oxidising agent as we go down the table.
Why is Fluorine a better oxidising agent than Iodine?
Fluorine can gain an electron more easily than Iodine.
What can we use to make colours more distinct when we want to know what halogen a colour is representing?
Cyclohexane can make colours more distinct.
What reaction can we do to prove which halogens are more reactive than others?
We can react a more reactive halogen with a less reactive halide ion to show that the halogen will take the halide ion’s electron. This is often called a displacement reaction.
What colour is Aqueous Chlorine normally?
A pale green solution.
What colour is Aqueous Chlorine with Cyclohexane?
A pale green solution.
What colour is Aqueous Bromine normally?
A yellow - orange solution.
What colour is Aqueous Bromine with Cyclohexane?
A red - orange solution.
What colour is Aqueous Iodine normally?
A brown solution.
What colour is Aqueous Iodine with Cyclohexane?
A purple solution.
What three displacement reactions (with a halogen and halide ion) result in a colour change?
Cl₂ + 2Br⁻ —> Cl⁻ + Br₂
Cl₂ + 2I⁻ —> Cl⁻ + I₂
Br₂ + 2I⁻ —> Br⁻ + I₂
What colour do we get when we add silver nitrate to chloride?
White Precipitate.
What colour do we get when we add silver nitrate to bromide?
Cream Precipitate.
What colour do we get when we add silver nitrate to Iodide?
Yellow Precipitate.
What is the halide ion test?
Add silver nitrate to an unknown halide solution and observe the colour of the precipitate.
If we are still not sure what substance the halide ion is after the halide ion test, what test can we do to be be even more sure?
We could add Ammonia Solution to see how soluble it is.
When ammonia solution is added, how does the solubility change as we go down the periodic table.
The solutions become less soluble.
What household product is NaClO found in?
Bleach.
What is the reaction when Chlorine is added to water?
Cl₂ + H₂O —> HCl + HClO
What is the reaction when Chlorine is added to sodium hydroxide?
Cl₂ + 2NaOH —> NaCl + NaClO + H₂O
What are the advantages of using Chlorine in water?
It kills bacteria.
What are the disadvantages of using Chlorine in water?
It’s toxic.
What are the advantages of using Fluoride in water?
It’s good at cleaning teeth.
What are the disadvantages of using Fluoride in water?
Some people believe that they should choose if fluorine is in he water or not. Too much fluoride can cause weaker bones.
