Group 7 Flashcards
Why is it important to add HNO3 before silver nitrate reaction?
To react with any carbonate ions which could be present and remove them as CO2.
Why can’t HCl be used before Iodine/silv nitrate?
Contains Cl^- ions which would react with the AgNO3
What can be seen from reaction between KBr and Cl2 without and with cyclohexane?
Without- orange
With- orange organic layer
What can be seen from reaction between KI and Cl2 without and with cyclohexane?
Without- yellow
With- purple at top
What can be seen from reaction between Br and KCl2 without and with cyclohexane?
No reaction
What can be seen from reaction between KI and Br2 without and with cyclohexane?
Without- brown
With- purple
What can be seen from reaction between I2 and KCl/KBr without and with cyclohexane?
No reaction
What is the additional test for Cl/Br/I that we must carry out as it is difficult to distinguish between white/cream/yellow?
Adding dilute and concentrated ammonia solution and utilising differences in solubility
What is AgCl soluble in (ammonia test relative)?
Soluble in dilute and concentrated solution
What is AgBr soluble in (ammonia test relative)?
Insoluble in dilute
Soluble in concentrated
What is AgI soluble in (ammonia test relative)?
Insoluble in dilute and concentrated ammonia solution
What can be observed from Cl, Br and I aqueous ions with silver nitrate solution?
Cl- white solid
Br- cream solid
I- yellow solid
What is the formula for adding Cl2 to water to kill bacteria?
Cl2 + H2O -> HCl + HOCl
What are the two main objections to use of Cl2 to kill bacteria in water?
- Cl2 is toxic so careful storage required.
- Cl2 can react with traces of organic compounds in water to make (possibly carcinogenic) chlorinated organic compounds.
What is the formula of bleach?
NaOCl
