C3.4 Analysis and Synthesis Flashcards Preview

GCSE Chemistry AQA > C3.4 Analysis and Synthesis > Flashcards

Flashcards in C3.4 Analysis and Synthesis Deck (30):
1

State the colour for the flame test of a Lithium Ion (Li+)

Crimson/red

2

State the colour for the flame test of a Sodium Ion (Na+)

Orange

3

State the colour for the flame test of a Potassium Ion (K+)

Lilac/Purple

4

State the colour for the flame test of a calcium ion (Ca2+)

red

5

State the colour for the flame test of a Barium Ion (Ba2+)

Green

6

State the observation when a few drops of sodium hydroxide is added to iron (II) chloride

green precipitate/solid

7

State the observation when a few drops of sodium hydroxide is added to iron (III) chloride

brown precipitate/solid

8

State the observation when a few drops of sodium hydroxide is added to copper chloride

blue precipitate/solid

9

State the observation when a few drops of sodiurecipitate/solidm hydroxide is added to calcium chloride

white precipitate/solid

10

State the observation when a few drops of sodium hydroxide is added to magnesium chloride

white precipitate/solid

11

State the observation when a few drops of sodium hydroxide is added to aluminium chloride

white precipitate/solid

12

State the observation when an excess of sodium hydroxide is added to aluminium chloride

precipitate dissolves/disappears

13

Describe how to distinguish between calcium and magnesium ions

flame test
calcium ions give a red flame

14

Describe the test for carbonate ions

Add an acid
Bubbles
of carbon dioxide
which turns limewater cloudy

15

Describe the test for sulphate ions

Add barium chloride
makes a white precipitate (solid)

16

Describe the test for chloride ions

Add silver nitrate
makes a white precipitate (solid)

17

Describe the test for bromide ions

Add silver nitrate
makes a cream precipitate (solid)

18

Describe the test for iodide ions

Add silver nitrate
makes a yellow precipitate

19

Give two advantages of using instrumental methods of analysis. [1]

fast
sensitive
accurate

20

Describe how to use apparatus to do a titration using 25 cm3 of dilute hydrochloric acid.
In your answer you should include:
• how you will determine the end point of the titration
• how you will make sure the result obtained is accurate. [4]

-put sodium hydroxide (alkali) in the burette
-add drop wise until the indicator turns pink
-whilst swirling
-read at the meniscus
-read the start and end volumes

21

What is meant by a closed system?

nothing can enter and nothing can leave the reaction

22

Explain why, when a reversible reaction reaches equilibrium, the reaction appears to have stopped. [2]

forward and backward reactions have same rate [1]
so there is no (overall) change in concentration of reactants and products [1]

23

Name a natural resource from which hydrogen is produced for the Haber process

methane (natural gas)

24

What happens to the amount of ammonia produced at equilibrium if the pressure is increased?
Give a reason for your answer. [2]

the amount (of ammonia) increases [1]
the equilibrium moves to the side (of the equation) with fewer (gaseous) molecules / moles [1]

25

Why is a temperature much lower than 450 °C not used for the Haber process? [1]

rate of reaction (too) slow [1]

26

Explain how ammonia is separated from unreacted nitrogen and hydrogen in the Haber process [2]

(gases) cooled [1]
ammonia condensed [1]

27

State and explain how a decrease in temperature would affect the yield of ammonia at equilibrium [2]

increase yield [1]
because (forward) reaction is exothermic [1]

28

Name a natural resource from which nitrogen is obtained for the Haber process

air

29

Name the catalyst used in the Haber process

Iron

30

Explain why high pressures need to be compromised in the Haber process

too expensive to maintain/requires large amounts of energy