mistakes

Question 1

what is the test for iron III

Answer 1

it is a cation.
add NaOH
a orange/brown precipitate forms

Question 2

what is the test for iron II

Answer 2

it is a cation.
add NaOH
a pale green precipitate forms

Question 3

what is the test for copper II?

Answer 3

it is a cation.
add NaOH
a blue precipitate forms

Question 4

what happens in a test for cations in general?

Answer 4

add NaOH
a precipitate fronms
note a hydroxide also forms

Question 5

what is the test for ammonia?

Answer 5

warm the mixture
ammonia gas is released
it turns damp red litmus paper blue

Question 6

what is the symbol for ammonia?

Answer 6

NH4+

Question 7

what is the test for a carbonate? what is the equation for this?

Answer 7

add dilute acid
bubble the casserole through limewater
limewater turns cloudy if an ion is present
there is also effervesense.

CO3 2- + 2H+ -> CO2 + H2O

Question 8

what is the test for halide ions?

Answer 8

• acidify the sample with nitric acid
  add silver nitrate AgNO3
  A silver halide precipitate forms (potassium nitrate and silver iodide for example)
  chloride: white
  bromide: cream
  iodine: yellow

Question 9

what colour does chloride go?

Answer 9

white

Question 10

what colouir does bromine go?

Answer 10

cream

Question 11

what colour does iodine go?

Answer 11

yellow

Question 12

what is the test for a sulfate ion? what is the equation?

Answer 12

SO4 2-
Add dilute HCl (must be HCL in order to remove any carbonates that may interfere with results)
- then add barium chloride or nitrate
- a white precipitate iwll form

Ba 2+ + SO4 2- -> BaSO4

Question 13

how woudl you carry out a flame test?

Answer 13

1. dip the loop of the ichrome wire into dilute acid. this is to prevent contaminating colours from mixing.
2. hold in a blue flame until there is no colour
3. dip the loop into solid smaple and place on the edge of the blue flame

Question 14

what colour does lithium go?

Answer 14

red

Question 15

what colour does sodium go?

Answer 15

yellow

Question 16

what colour does potassium go?

Answer 16

lilac

Question 17

what colour foes calcium go?

Answer 17

orange-red

Question 18

what colour does copper go?

Answer 18

blue-green

Question 19

what metal burns wiht a white flame?

Answer 19

magnesium

Question 20

what are the tests for the gases

Answer 20

ammonia - damp yed litmus paper turns blue
co2 - limewater turns cloudy
cl2- dambp blue litmus paper turns red
h2 - burning splint gives a squeeky pop
o2 - relights glowing splint

Question 21

what is the test for water - physical

Answer 21

boiling point
100 degrees
impuritirs tend to raise boiling point

Question 22

what is the chemical test for water

Answer 22

anhydrous copper sulfate
it turns blue

Question 23

what are the solubility rules? - which are soluble?

Answer 23

1. all sodium, potassium and ammonium. (metal)
2. all nitrates (metal)
3. most chlorides (silver and lead II)
4. and sulfate (barium, lead II, calcium).
5. cabronates of sodium, porassium, and ammonium.
6. hydroxides of sodium, potassium, and ammonium. (calcium sparingly)

Question 24

solibility rules - which are insoluble?

Answer 24

those that arent sodium, potassium, nitrates
silver and lead chloride.
barium, lead IIn and calcium chloride
most carbonates except soodium, potassium, ammonium
most hydroxides (but sodium, potassium, and ammonia)

Question 25

in the thermal decomposition of copper carbonate, what is the colour change?

Answer 25

green do dark powder

Question 26

tell me about the greenhouse effect:

Answer 26

short wavelength radiation is emitted from the sun. when it reaches earth, some of it is absorbed but some is re - emitted as long wavelength radiation this may be trapped in earth's atmosphere by greenhouse gases and absorb and store energy

Question 27

how woudl you prepare a soluble salt?

Answer 27

acid + insoluble salt: 1. add the insoliublr salt in excess (ensuring that the acid doesnt become dangerously concentrated in the evaporation and crystallisation)( 2. the excess reactant is removed by filtration 3. so only salt and water is left - evaporate some water 5. pat dry 6. may take several days for crystals to form

Question 28

how else could you prepare a soluble salt (technical)?

Answer 28

titration: 1. alkali and indicator in conical flask using a pipette 2. add acid using a burette, noting startting colume and add until you get an average 3. you can do it dorp wide 4. repeat without indicator 5. transfer some solution to evaporating basin to evaporate some water 6. pat dry

Question 29

how woudl you prepare an insoluble salt? what is this experiment callerd?

Answer 29

precipitation reaction 1. must be insolble in water 2. soluble salt + soluble salt - insoluble salt and soluble alt 3. add 1 solt solution and then another until it is in slight excess ensuring the max precipitate is made. 4. use a stirring rod to mix 5. filter 6. wahs in distilled water to remove reactants contaminating the residue 7. leave to dry

Question 30

what will the reaction sth an insoluble salt that makes a salt look like in the exam?

Answer 30

X (aq) + Y (aq) -> Z (s) + A (aq)

Question 31

what is metal and acid?

Answer 31

salt and hydrogen

Question 32

what is metal oxide and acid

Answer 32

salt and water

Question 33

metal carbonate and acid?

Answer 33

salt and water and carbon dioxide

Question 34

what is the colour change of an indicator - litmus?

Answer 34

red - acid blue - alkali

Question 35

what is the colour change of an indicator - phenolthelein?

Answer 35

colourless ot pink acid to alkali

Question 36

what is the colour change of an indicator - methyl orange?

Answer 36

red to yellow acid to alkali