Chemical analysis

Question 1

What is a Pure substance?

Answer 1

It is a substance that contains only one compound or element nothing mixed.

Question 2

How can you test the purity of a substance

Answer 2

by measuring its melting and boiling point and comparing it to the actual boiling and melting point of the substance using the data book

Question 3

If the melting and boiling point is closer to the actual melting and boiling point what does it tell you about the substance?

Answer 3

The more pure the substance is

Question 4

How do you know if a substance is impure?

Answer 4

They have a range of melting and boiling points compared to their actual points.

Question 5

How do you know the presence of a impure substance?

Answer 5

If the melting point is lower

If the boiling point increases.

Question 6

What are formulations?

Answer 6

Useful mixtures with precise purpose that are made by following a formula.

Question 7

Paint is a formulation composed of what?

Answer 7

Pigment
Solvent
Binder
Additives

Question 8

What is a solvent?

Answer 8

A substance that causes things to dissolve

Question 9

Give an example of solvent?

Answer 9

water

Question 10

What is a solute?

Answer 10

A substance that dissolves

Question 11

Give an example of a solute?

Answer 11

Pen dot

Question 12

What is Chromatography?

Answer 12

is an analytical method used to separate the substance in a mixture, which can be used to identify substances.

Question 13

What are the 2 phases of chromatography?

Answer 13

A mobile phase

A stationary phase

Question 14

What is a mobile phase?

Answer 14

Where the molecules can move, this is always a liquid or a gas

Question 15

What is the Stationary phase?

Answer 15

Where the molecules can’t move, this can be a solid or a really thick liquid.

Question 16

During chromatography what does the Mobile phases move through?

Answer 16

A stationary phase

Question 17

What is the stationary phase in Paper chromatography?

Answer 17

Filter paper

Question 18

What is the Mobile phase in Paper chromatography?

Answer 18

The water

Question 19

If a substance is less soluble what does it mean?

Answer 19

Travels less distance on the filter paper

Question 20

If a substance is more soluble what does this mean?

Answer 20

Travels further

Question 21

What does RF mean?

Answer 21

Retention factor

Question 22

If a substance has a larger RF what does it mean?

Answer 22

More soluble in the solvent

Question 23

If a substance has a smaller RF what does it mean?

Answer 23

Less soluble in the solvent

Question 24

How do you calculate the retention factor (RF)?

Answer 24

Distance traveled by the substance/ Distance traveled by solvent.

Question 25

What are the 4 common gas tests?

Answer 25

Chlorine
Oxygen
Carbon dioxide
Hydrogen

Question 26

How do you test for chlorine?

Answer 26

Put litmus paper in chlorine and turns the paper white

Question 27

How do you test for oxygen?

Answer 27

Put a glowing splint in side a test tube and the oxygen will light up again.

Question 28

How do you test for Carbon dioxide?

Answer 28

Have a test tube of calcium carbonate with Hydrocholric acid and have a test tube of lime water(Calcium hydroxide) put a gas syringe in the calcium carbonate and hydrochloric acid then put it in the test tube of lime water and if their are bubbles their is CO2.

Question 29

How do you test for Hydrogen?

Answer 29

Light a splint then put it in a test tube containing hydrogen which will make a squeaky pop.

Question 30

What is Limewater?

Answer 30

Calcium hydroxide dissolved in water (aqueous).