Group 17 Flashcards
What is the test for the iodide ion?
Add aqueous silver nitrate solution, which will form a yellow precipitate ; this precipitate will not dissolve in concentrated aqueous ammonia
Write the balanced chemical equation with state symbols for the disproportionation reaction of chlorine with hot aqueous sodium hydroxide
3Cl2 (g) + 6NaOH(aq) –> NaClO3(aq) + 5NaCl(aq) + 3H2O(l)
What are the reasons for the trend in reactivity of the halogens down group 7?
The ease of gaining electron’s (first electron affinity) decreases
Why is an organic solvent used after reacting halogens with halides in aqueous solution?
To more easily distinguish bromine from iodine, which are both orange/brown in aqueous solution
What is the trend in the boiling points of the halogens down group 7?
They increase due to the number of strength of LDFs between molecules increases
What does this reaction confirm for us?
Cl2(aq) + 2KBr(aq) -> 2KCl(aq) + Br (aq)
Chlorine is more reactive than bromine and chlorine is a better oxidising agent than bromine.
What is the trend in reactivity of halogens down group 7?
They get less reactive down the group
Write the balanced chemical equation, with state symbols for the disproportionation reaction of chlorine with water.
Cl2 (g) + H2O (l) -> HOCl (aq) + HCl (aq)
What colour is iodine dissolved in an organic solvent?
Purple
What is the change in oxidation state of both elements in this reaction?
Sr (s) + Br2 (l) SrBr (s)
Br: 0 to -1
Sr: 0 to +2
Write the balanced chemical equation with state symbols for the disproportionation reaction of chlorine with cold dilute aqueous sodium hydroxide
Cl2 (g) + 2NaOH (aq) -> NaOCl (aq) + NaCl (aq) + H2O (l)
What are the reasons for the trend in boiling points of the halogens down group 7?
London forces increase with the number of electrons, so as atomic number increases down the group, the strength of the intermolecular forces increases
