Elements Of Life

Question 1

Which of Lead Chloride, lead bromide, copper iodide, and lead iodide is yellow?

Answer 1

Lead iodide

The rest are white

Question 2

What colour is copper carbonate?

Answer 2

Blue/Green

Question 3

What colour is silver carbonate?

Answer 3

Yellow

Question 4

What colour are most carbonate precipitates?

Answer 4

White

Question 5

How do you get pure salt from a precipitation reaction?

Answer 5

1) wait for it to precipitate out
2) filter
3) wash
4) dry on filter paper

Question 6

What do you need to make a soluble salt

Answer 6

Metal or insoluble base (metal hydroxide or oxide)

Question 7

What does ‘spin pairing’ mean?

Answer 7

Electrons in orbitals ‘spin’ in opposite directions

Question 8

What is the shape of a molecule with 2 electron pairs?

Answer 8

Linear

Question 9

What is the shape and how many electrons can:

1) an S orbital hold?
2) a p orbital hold?
3) how many electrons can a D orbital hold?

Answer 9

1) sphere - 2 electrons
2) dumbbell - 6 electrons
3) 10 electrons

Question 10

What are the shapes of a molecule with 3 electron pairs?

1) without a lone pair?
2) with a lone pair?

Answer 10

1) trigonal planar

2) bent

Question 11

What are the shapes of a molecule with 4 electron pairs?

1) no lone pairs
2) 1 lone pair
3) 2 lone pairs

Answer 11

1) tetrahedral
2) trigonal pyramidal
3) bent

Question 12

What shape would a molecule with 5 electron pairs have?

Answer 12

Trigonal bipyramidal

Question 13

What shape would an electron with 6 electron pairs have?

Answer 13

Octahedral

Question 14

Which metal ions precipitation starts white and redissolves to colourless?

Answer 14

Zinc(II) and aluminium(III)

Question 15

How do group 2 elements produce metal hydroxides

Answer 15

1) react with water
Or
2) burn in oxygen to form metal oxide and then dissolve to form metal hydroxide

Question 16

What group 2 type breaks down into CO2 and metal hydroxides?

Answer 16

Group 2 carbonates

Question 17

What are the solubility trends of group 2

1) hydroxides
2) carbonates

Answer 17

1) less soluble down the group

2) more soluble down the group

Question 18

What is the trend in thermal stability of group 2 carbonates?

Answer 18

More stable down the group

Question 19

What reactions show that group 2 oxides are a base?

Answer 19

1) react with water to form hydroxides - very alkaline

2) neutralise acids

Question 20

What do group 2 carbonates decompose to?

Answer 20

Group 2 oxide and CO2

Question 21

What reaction makes salts?

Answer 21

Neutralisation reaction with an acid and a base

Question 22

Which of a cation or anion is positive or negative?

Answer 22

Cation = positive (cats)
Anion = negative

Question 23

What is the formula of the ammonium cation?

Answer 23

NH4+

Question 24

What is the formula of nitrate?

Answer 24

NO3-

Question 25

What is OH- called

Answer 25

Hydroxide

Question 26

What is the formula of a sulfate

Answer 26

SO4^2-

Question 27

What colour is a silver ion in as a precipitate? Ag+

Answer 27

Brown

Question 28

What colour is a calcium ion (Ca^2+) as a precipitate?

Answer 28

White

Question 29

What metal ion is has a blue precipitate?

Answer 29

Copper | Cu^2+

Question 30

What metal ion has a green precipitate?

Answer 30

Iron (II) | Fe^3+

Question 31

What colour is a lead ion as a precipitate? Pb^2+

Answer 31

White

Question 32

What metal ion has a reddish brown precipitate?

Answer 32

Iron (III) | Fe^3+

Question 33

How do you test for a coloured precipitate of a metal ion?

Answer 33

Metal ion + hydroxide solution (NaOH) | Forms an insoluble metal hydroxide which has a coloured precipitate which can be used to identify metal ion

Question 34

What are the two ways to test for ammonium compounds?

Answer 34

1) damp red litmus paper to test for ammonia gas - paper will go blue if ammonia is present because it’s alkaline 2) Ammonium ions - add NaOH and gently heat ammonia gas is given off which can be tested with red litmus paper

Question 35

What is a test for hydroxides

Answer 35

Red piece of litmus paper into solution - OH- is alkaline so paper will go blue if present

Question 36

How do you test tor nitrates?

Answer 36

1) warm solution with NaOH and aluminium foil (aluminium to reduce nitrate ions to ammonium ions) 2) NH4+ reacts with OH- to form ammonia gas and water 3) test for ammonia with damp red litmus paper 4) if ammonia is present it contains nitrate ions

Question 37

What colour is a barium ion (Ba2+) in a flame test?

Answer 37

Apple green

Question 38

What does a blue green flame in a flame test mean?

Answer 38

Copper ions | Cu2+

Question 39

What does a crimson flame mean in a flame test?

Answer 39

Lithium (Li+)

Question 40

What colour is a potassium ion in a flame test?

Answer 40

Lilac

Question 41

What colour is a sodium ion in a flame test?

Answer 41

Orange-yellow

Question 42

What colour is a calcium ion in a flame test?

Answer 42

Brick red

Question 43

How do you test for sulfate ions?

Answer 43

Add dilute HCl followed by barium chloride solution (BaCl2) | If a white precipitate forms sulfate is present (precipitate is barium sulfate)

Question 44

What are the results of the test of halides with silver nitrate solution

Answer 44

``` Chloride = white Bromide = cream Iodide = yellow ```

Question 45

What order should you do tests for to avoid false positives?

Answer 45

Carbonates —> sulfates —> halides

Question 46

How do you carry out a flame test?

Answer 46

1) dip a nichrome wire loop in conc HCl 2) dip loop in sample of compound 3) hold in clear blue flame 4) observe colour change

Question 47

What two solutions do you need to test to test for halides?

Answer 47

Dilute nitric acid (removes sulfate ions) and then silver nitrate solution

Question 48

How do you test for metal ions?

Answer 48

Add a few drops of NaOH to a solution of the compound to form an insoluble metal hydroxide

Question 49

What is the order of electromagnetic radiation? In increasing frequency and decreasing wavelength

Answer 49

``` Radio waves Micro waves Infrared radiation Visible light Ultra Violet Xrays Gamma rays ```

Question 50

How do electrons move energy levels?

Answer 50

Absorb energy to move up energy levels Release energy to move down (Fixes amounts of energy)

Question 51

What does an absorption spectra look like?

Answer 51

Coloured background with black lines | Corresponding to the frequencies in order to change energy level

Question 52

What does an emission spectra look like?

Answer 52

Black background with coloured lines

Question 53

Equation for energy

Answer 53

E= hv | Energy (J) = h x frequency (Hz)

Question 54

Equation for wavelength

Answer 54

Wavelength (m) = c/frequency

Question 55

What is nuclear fusion? | How much energy does it release?

Answer 55

When two small nuclei combine under high pressure and temp (usually in stars) Releases a lot of energy

Question 56

Why do lines on an absorption and emission spectra get closer together at higher frequencies?

Answer 56

Energy levels get closer together with increasing energy

Question 57

What salts are insoluble?

Answer 57

``` Carbonates Apart from Lithium Ammonium Potassium and Sodium (LAPS) Or copper or silver (Copper carbonate is blue-green Silver carbonate is yellow) ```

Question 58

What salts are soluble?

Answer 58

Lithium Ammonium Pottasium Sodium (LAPS) Nitrates Most chlorides bromides and upsides (not leads or silver halides) Most sulfate (not barium calcium or lead)

Question 59

How can you test for carbonates?

Answer 59

HCL + carbonate | Produces CO2 which turns lime water cloudy

Question 60

What is the formula of carbonate

Answer 60

CO3^2-

Question 61

What is the formula of hydrogen carbonate?

Answer 61

HCO3^2-

Question 62

What is the equation to calculate percentage yield?

Answer 62

Percentage yield = (actual yield/theoretical yield) x 100

Question 63

What is the ionic equation for a halide reaction with silver nitrate solution that produces a yellow precipitate?

Answer 63

Ag+ + I- —> AgI

Question 64

What is the ionic equation for a halide reaction with silver nitrate solution that produces a cream precipitate?

Answer 64

Ag+ + Br- —> AgBr

Question 65

What is the ionic equation for a halide reaction with silver nitrate solution that produces a white precipitate?

Answer 65

Ag+ + Cl- —> AgCl

Question 66

What is an ionic reaction?

Answer 66

A reaction which show how dissociated ions react