Chemistry

Question 1

Relative mass of an electron

Answer 1

1/200

Question 2

Using a mass spectrometer

Answer 2

…

Question 3

Relative atomic mass

Answer 3

The average mass of one atom compared to 1/12 of the mass of one atom of carbon-12

Question 4

Group 2

Answer 4

Alkaline earth metals

Question 5

Going down a metal group

Answer 5

Reactivity increases

Question 6

Going down a non-metal group

Answer 6

Reactivity decreases

Question 7

In a chemical reaction

Answer 7

New substances are formed by the rearrangement of atoms and their electrons, but no nuclei are destroyed or created

Question 8

Factors affecting equilibrium position

Answer 8

Concentration
Temperature
Pressure

Question 9

Relative molar mass

Answer 9

Is this the same as relative molecular mass?

Question 10

Avogadros number

Answer 10

Number of particles in one mole of substance

Question 11

Grams -> moles

Answer 11

Divide grams by molar mass

Question 12

Calculating solubility

Answer 12

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Question 13

Ionic bonding

Answer 13

Transfer of electrons from metals to non metals creates ions

Opposite charged ions attract

Question 14

When to apply centrifugation

Answer 14

used for the separation of particles from a solution according to their size, shape, density and viscosity

Question 15

When do apply dissolving

Answer 15

Separate soluble and insoluble

Question 16

Establishing purity using chromatography

Answer 16

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Question 17

Why is direct current used in electrolysis

Answer 17

Means anions go to anode and cations go to cathode

If alternating current was used, it would lead to uneven disposition of the ions at the electrodes

Question 18

At the cathode

Answer 18

Cations are reduced

Question 19

At the anode

Answer 19

Anions are oxidised

Question 20

Aqueous electrolysis

Answer 20

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Question 21

As carbon chain length increases, boiling point.

Answer 21

Increases

Question 22

As carbon chain length increases, viscosity

Answer 22

Increases

Question 23

As carbon chain length increases, flammability

Answer 23

Decreases

Question 24

Alkene addition with steam (hydration)

Answer 24

Conditions:
300-600
70atm
H3PO4

alkene -> alcohol

No waste product, easy cheap - high atom economy

H+ and OH- added

Question 25

Alcohols + sodium

Answer 25

Effervescence (hydrogen) Mixture gets hot Sodium dissolved Sodium alkoxide is produced (white solid) Test for alcohols

Question 26

Carboxylic acids

Answer 26

CnH2n+1COOH

Question 27

Metal reactivity

Answer 27

Tendency to form positive ions and the ease of extraction of the metal

Question 28

Metal extraction

Answer 28

Involved reduction processes

Question 29

Transition metals

Answer 29

1. Able to form stable ions in different oxidation states 2. Often form coloured compounds 3. Often used as ionic or atomic catalysts

Question 30

Chlorine test

Answer 30

Damp blue litmus turns red and is then bleached

Question 31

Metal + NaOH

Answer 31

1. Al3+, Ca2+, Mg2+ -> white ppt 2. Cu2+ -> blue ppt 3. Fe2+ -> green ppt 4. Fe3+ -> brown ppt

Question 32

Flame tests

Answer 32

Li - crimson red Na - yellow orange Ca - red-orange

Question 33

Fractional distillation can be used to

Answer 33

Separate the components of air

Question 34

Origins of greenhouse gases

Answer 34

Burning fossil fuels

Question 35

Effects of greenhouse gases

Answer 35

Absorbs IR from the sun (which is absorbed and re-radiated at a lower frequency) and convert to heat energy, warming the atmosphere

Question 36

Treating water

Answer 36

With chlorine: hydrochloric and chloric (1) acid which act as disinfectants (oxidising agent) Kills bacteria by oxidation pH is treated by adding calcium hydroxide

Question 37

First and successive ionisation energies in group 2

Answer 37

* decreases * distance from nucleus increases * greater shielding

Question 38

First and successive ionisation energies in period 3

Answer 38

* increase * electrons are added to the same electron shell (same distance) * nuclear charge increases; attraction increases * more energy needed for removal

Question 39

Kinetic energy

Answer 39

1/2mv^2

Question 40

Describe the workings of a TofF spectrometer

Answer 40

...

Question 41

Electronegativity

Answer 41

The tendency of an atom to attract a shared pair of electrons

Question 42

Group 2 metals + oxygen

Answer 42

``` • except Be, they all react vigorously - bright flame • Mg -> bright white flame • Ca + Sr -> red flame • Ba -> green flame Except Ba: • 2M + O2 -> 2MO • Ba + O2 -> 2BaO2 (peroxide ion O22-) ```

Question 43

Group 2 metals + water

Answer 43

• Be does not react • Mg reacts v slowly w/ cold water. W/ steam -> MgO + H2 • Ca, Sr and Ba react w/ cold water with increasing vigour: -> hydroxide + hydrogen * Ca(OH)2 -> sparingly soluble in water; effervescence, thick white suspension * Sr(OH)2 -> is slightly soluble * Ba(OH)2 -> soluble

Question 44

Group 2 metal oxides + water

Answer 44

* BeO mot attacked | * other hydroxides

Question 45

Group 2 hydroxide solubility

Answer 45

Solubility increases down the group

Question 46

Group 2 sulphate solubility

Answer 46

Solubility decreases down the group

Question 47

Thermal décomposition of group 2 metal carbonates

Answer 47

Metal oxide + CO2

Question 48

Cold aqueous NaOH + chlorine

Answer 48

Cl2 + 2NaOH -> NaOCl + NaCl

Question 49

Water + chlorine

Answer 49

As before

Question 50

Concentrated sulphuric acid reactions

Answer 50

Chloride: -> KHSO4 + HCl Bromide: - > same as above - > KBr + H2SO4 -> Br2 + SO2 + 2H2O Iodide: - > same as above - > same as above

Question 51

Reducability of halide ions

Answer 51

Iodide is the strongest reducing agent

Question 52

Atomic ratio explanations in group 1,2 and 7

Answer 52

Obvious

Question 53

First ionisation energy explanation in groups 1,2 and 7

Answer 53

Decreases for same reason as before

Question 54

Boiling point in groups 1,2 and 7

Answer 54

...

Question 55

Melting and boiling points in periods 2 and 3

Answer 55

...

Question 56

First ionisation energy in periods 2 and 3

Answer 56

Increases for same reason as before

Question 57

Atomic radii in periods 2 and 3

Answer 57

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Question 58

Electronegativity in periods 2 and 3

Answer 58

...

Question 59

Cycloalkanes

Answer 59

CnH2n

Question 60

Elimination

Answer 60

Removal of a small molecule for an organic molecule E.g. ethanolic élimination of halogenoalkanes

Question 61

How does bond polarity influence reactivity

Answer 61

Z...