Tests For Ions

Question 1

Test for group 2 ions using

Answer 1

Flame tests

Question 2

Flame tests

Answer 2

These are used to identify group 2
ions in a solid sample.

They can be made into solutions and sprayed on the Bunsen too,

however this may be difficult if the sample being tested is insoluble.

Question 3

Procedure for flame tests

Answer 3

1. Dip the nichrome wire in concentrated hydrochloric acid
2. Dip into sample
3. Place the loop into the BLUE Bunsen flame and observe the colour

Question 4

Dark red from flame test group 2 ion

Answer 4

Calcium

Question 5

Red from flame test group 2 ion

Answer 5

Strontium

Question 6

Green from flame test group 2 ion

Answer 6

Barium

Question 7

Test for ammonium compounds and hydroxides using..

Answer 7

Litmus paper

Question 8

Testing for ammonium compounds

Answer 8

Add sodium hydroxide (NaOH)
gently heat,

and if ammonium compound present ammonia gas will be produced.

Use damp red litmus. Ammonia
will dissolve in the water and turn
litmus blue.

Question 9

Test for hydroxides

Answer 9

Hydroxides are alkaline and they will turn red litmus blue.

This test doesn’t mean you will definitely have hydroxides. Red litmus turns blue for any alkali.

Further tests are needed to confirm you have an alkali.

Question 10

Test for carbonates and Sulfates using….

Answer 10

Hydrochloric acid and barium chloride

Question 11

Testing for carbonates

Answer 11

Hydrochloric acid reacts with
Carbonates to make CO2 gas.

When bubbled through
limewater it turns cloudy.

Question 12

Testing for sulfates

Answer 12

1. Add hydrochloric acid (HCI) to
   remove any carbonates in. These
   could precipitate out after adding
   barium chloride giving a false result.

2.Add barium chloride

White precipitate forms (barium Sulfate - insoluble)

Question 13

Order for test for ions

Answer 13

Test for carbonates

Test for sulphates

Test for halides