Chemical analysis-Chemistry paper 2

Question 1

Define formulation

Answer 1

It is a mixture that has been designed to produce a useful product.

Question 2

What is meant by impurity?

Answer 2

This is where there is another substance that makes a pure substance impure.

Question 3

Define insoluble

Answer 3

A substance that does not dissolve in a solvent.

Question 4

Define soluble

Answer 4

A substance that dissolves in a solvent.

Question 5

Define solvent

Answer 5

the liquid that can dissolve a solute into it.

Question 6

what is meant by the term precipitate?

Answer 6

This is the solid that is produced froma reaction.

Question 7

what is a positive ion?

Answer 7

An atom that has lost electrons to form positive ions.

Question 8

what is a negative ion?

Answer 8

An ion that has gained electrons to form a negative charge.

Question 9

What is the retention factor in chromotography?

Answer 9

It is a measurement from chromotography, it is the distance that a spot of substance has been carried above the baseline divided by the distance of the solvent front.

Question 10

What is the test for oxygen?

Answer 10

If oxygen is present it relights a glowing splint.

Question 11

What is the test for hydrogen?

Answer 11

If hydrogen is present it makes a squeaky pop with a glowing splint.

Question 12

What is the test for carbon dioxide?

Answer 12

if carbon dioxide is present then it turns limewater cloudy.

Question 13

how do we calculate the rf value?

Answer 13

The distance moved by substance divided by the distance moved by solvent.

Question 14

What do metal hydroxides appear as if they are insoluble?

Answer 14

They appear as precipitates.

Question 15

Different metals from diffeerent coloured precipitates when reacted with sodium hydroxide.

What precipitate do each of these metal ions form?
1.) Aluminimum
2.) Calcium
3.) magnesium
4.) Copper
5.) Iron(2)
6.) Iron(3)

Answer 15

1.) white
2.) white
3.) white
4.) blue
5.) green
6.) brown

Question 16

How is a formulated product formed?

Answer 16

it is formed by mixing the components in carefully measured quantities to ensure that the product has the required properties.

Question 17

Different halides produce different coloured insolubleprecipitates when reacted with silver ions.

What precipitate colur do these halide ions form?
1.) Chlorine
2.) Bromide
3.) Iodide

Answer 17

1.) white
2.)cream
3.)yellow

Question 18

What is the flame test method how is it performed?

Answer 18

The flame test methods identify different metals because they produce different colours.
The method is performed by dipping a wire loop into a sample then placing into the blue flame of a bunsen burner.

Question 19

What colours do these metals show if they are presnt in a flame test?
1.) Sodium
2.) Potassium
3.) Calcium
4.) Copper
5.) Chromium/Lithium.

Answer 19

1.) yellow
2.) Lilac(purple)
3.) calcium(orange/red)
4.) blue
5.) crimson red

Question 20

How do you test for carbonates? and prove carbon dioxide is pesent?

Answer 20

Carbonate ions react with a dilute acid such as hydrochloric acid and produce carbon bubbles.
The gas can be collected and passed through limewater to prove that it is carbon dioxide.

Question 21

How do you test for sulfates

Answer 21

Suldate ions react with barium chloride (when acidified) to produce insoluble barium sulfate.