HW

Question 1

What are all the colours of Cations?

Answer 1

Sodium: Yellowish
Potassium: Lilac
Calcium: Orange
Lithium: Red
Barium: Greeny white/blueish white
Copper: Green
Lead: Paleish blue
Copper: Blue

Question 2

How to carry out flame tests?

Answer 2

Dip the nichrome wire in acid to clean it, then dip the wire into the salt and finally burn it to see if there is a cation present.

Question 3

How to test for NH4+:

Answer 3

Add NaOH, warm gently, then test gas given off with red litmus paper and it will turn blue if Ammonia is present.

Question 4

Testing for chloride, bromide…

Answer 4

Chloride (Cl-)
using dilute nitric acid and Silver Nitrate solution
Sulphate (SO42-)
using dilute hydrochloric acid and Barium Chloride solution
Carbonate (CO32-)
using dilute hydrochloric acid and identifying the Carbon Dioxide evolved, using limewater
Nitrate (NO3-)
using NaOH and aluminum, then warming gently.

Question 5

Solubility rules:

Answer 5

Soluble: All sodium and potassium salts
All Nitrates
Most chlorides, bromides and iodides
Most sulfates
Sodium, potassium and ammonium carbonates

Insoluble: Silver and lead chlorides, bromides and iodides
Lead sulfate and barium sulfate
Most other carbonates

Question 6

Colours of precipitates:

Answer 6

A full table in my book