C5.8- Chemical Analysis

Question 1

What is a pure substance?

Answer 1

Substance made from one element or compound

Question 2

What is an element?

Answer 2

A substance made up of only one type of atom

Question 3

What is a compound?

Answer 3

2 or more elements chemically bonded

Question 4

What is a mixture?

Answer 4

2 or more elements or compounds not chemically bonded

Question 5

What is a formulation?

Answer 5

A mixture of different substances at set values. Designed

Question 6

What is paper chromatography used for?

Answer 6

To separate mixtures of soluble susbstances

Question 7

What is the stationary phase in paper chromatography?

Answer 7

Paper

Question 8

What is the mobile phase in paper chromatography?

Answer 8

Solvent chosen

Question 9

What causes the substances to travel at different rates?

Answer 9

The attraction to the phases in different proportions

Question 10

What is the test for hydrogen?

Answer 10

Expose to a lot splint and a pop should be heard

Question 11

What is the test for oxygen?

Answer 11

Expose to a glowing splint and it should relight

Question 12

What is the test for carbon dioxide?

Answer 12

Bubble through limewater, should turn cloudy

Question 13

What is the test for chlorine?

Answer 13

Expose to damp litmus paper, should bleach

Question 14

What is the test for potassium (K+)?

Answer 14

Flame test
Lilac

Question 15

What is the test for copper (Cu2+)?

Answer 15

Flame test
Green

Question 16

What is the test for sodium (Na+)?

Answer 16

Flame test
Orange/yellow

Question 17

What is the test for lithium (Li+)?

Answer 17

Flame test
Crimson

Question 18

What is the test for calcium (Ca2+)?

Answer 18

Flame test
Orange/red

Question 19

What is the test for barium (Ba2+)?

Answer 19

Flame test
Green

Question 20

What is the test for aluminium (Al3+)?

Answer 20

Sodium hydroxide
White precipitate that dissolves in excess NaOH

Question 21

What is the other test for copper (Cu2+)?

Answer 21

Sodium hydroxide
Blue precipitate

Question 22

What is the test for iron (Fe3+)?

Answer 22

Sodium hydroxide
Red/brown precipitate

Question 23

What is the test for iron (Fe2+)?

Answer 23

Sodium hydroxide
Green precipitate

Question 24

What is the test for magnesium (Mg2+)?

Answer 24

Sodium hydroxide
White precipitate

Question 25

What is the other test for calcium (Ca2+)?

Answer 25

Sodium hydroxide
White precipitate

Question 26

Which test is for cations?

Answer 26

Sodium hydroxide

Question 27

What is the test for sulfates?

Answer 27

Add dilute hydrochloric acid and add barium chloride.
White precipitate

Question 28

What are the tests for halides?

Answer 28

Add dilute nitric acid and add silver nitrate.
Cl- white
Br- cream
I- yellow

Question 29

What is the test for carbonates?

Answer 29

Add dilute acid.
CO2 produced

Question 30

What is the test for nitrate ions (NO3-)?

Answer 30

Add sodium hydroxide and aluminium powder. Warm solution in Bunsen flame. Hover red litmus paper over.
Litmus paper turns blue.

Question 31

What is the test for ammonium?

Answer 31

Add dilute sodium hydroxide and warm.
Turns red litmus paper blue.

Question 32

What is flame emission spectroscopy used for?

Answer 32

Used to identify ions in mixtures

Question 33

What are the advantages of instrumental techniques?

Answer 33

Do not damage substance during testing.
More sensitive than other chemical techniques.
Identify all substances in a mixture.
Only requires tiny amount of substance.
Reliable and accurate.
Quick.

Question 34

What are the disadvantages of instrumental techniques?

Answer 34

Test results often require expert interpretation