Unit 3 - Analysis (Testing For Positive And Negative Ions) Flashcards Preview

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Flashcards in Unit 3 - Analysis (Testing For Positive And Negative Ions) Deck (25):
1

What colour does lithium go in a flame?

Crimson

2

What colour does sodium go in a flame?

Yellow

3

What colour does potassium go in a flame?

Lilac

4

What colour does calcium go in a flame?

Red

5

What colour does barium go in a flame?

Green

6

When doing a flame test, how do you make sure the wire loop is completely clean?

By dipping in into hydrochloric acid and rinsing it with distilled water

7

What is the other test for metal ions?

Sodium hydroxide test - Add a few drops of sodium hydroxide solution to a solution of the unknown substance

8

What colour does the precipitate go for Calcium

White

9

What colour does the precipitate go for copper

Blue

10

What colour does the precipitate go for iron (II)?

Green

11

What colour does the precipitate go for iron (III)?

Brown

12

What colour does the precipitate go for aluminium?

White - at first
It then redissolves in excess NaOH to form a colourless solution

13

What colour does the precipitate go for magnesium?

White

14

Is the metal iron the positive or negative ion?

Positive

15

How can you test for metal ions?

Putting the substance in a flame

16

How do you test for carbonates?

Test for carbon dioxide - you can test to see if a gas is carbon dioxide by bubbling it through limewater
If it's lime water: the limewater goes cloudy
You can use this test for carbonate ions since carbonates react with dilute acid to form carbon dioxide

17

How do you test for Halide ions? (Chloride, bromide and iodide)

Add dilute nitric acid followed by silver nitrate solution

18

Testing for negative ions: What precipitate does chloride give?

White Percipitate of Silver chloride

19

Testing for negative ions: what precipitate does bromide give

A cream ppte of silver bromide

20

Testing for negative ions: what ppte does iodide give

A yellow ppte of silver iodide

21

How do you test for sulfate ions? (

Add dilute HCL followed by barium chloride solution

22

Testing for negative ions: sulfate ions: what does a white ppte of barium sulfate mean?

The original compound was sulfate

23

Testing for negative ions: what result does carbonate give?

Effervescence

24

Testing for negative ions: what result does sulfate give?

White ppte

25

Testing for negative ions: what result does nitrate give?

Moist red litmus paper placed in the mouth of the tube turns blue