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Wrong Exam Qs > physical chemistry🧪 > Flashcards

physical chemistry🧪 Flashcards

1
Q

explain the trend in atomic radius from li to f

A
  • atomic radius decreases
  • increase in proton number
  • electrons experience same shielding as same number of shells
  • increase in nuclear attraction
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2
Q

state conditions and reagents for making bleach

A
  • cold and dilute naoh

- chlorine

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3
Q

what is disproportionation

A

the simultaneous oxidation and reduction of the same element

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4
Q

equation for decomposition of calcium carbonate

A

caco3 (s) —> cao (s) + co2 (g)

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5
Q

which group 2 carbonate decomposes at highest temperature

A

BaCO3 or RaCO3

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6
Q

predict structure and bonding of Ba3N2

A

-giant ionic lattice

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7
Q

what second reagent is used to confirm halide test and results

A
  • nh3
  • agcl dissolves in dilute nh3
  • agbr dissolves in concentrated nh3
  • agi does not dissolve
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8
Q

when talking about ionisation energy of carbon why is it important to distinguish between diamond and graphite

A

diamond and graphite form gaseous atoms of carbon when ionised

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9
Q

force overcome when melting fluorine

A

induced dipole

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10
Q

in lithium, between which particles are metallic bonds acting

A

li+ ions and delocalised electrons

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11
Q

Al MP= 660
Si MP=1410
P MP= 44
explain trend in terms of bonding and structure

A
  • silicon has giant covalent structure
  • aluminium has giant structure and metallic bonds
  • phosphorus has simple covalent molecules with induced dipole forces between molecules
  • metallic and covalent bonds are stronger than induced dipole forces
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12
Q

-strontium sulfate (iv) why is roman numeral used

A

-sulfur has many oxidation states

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13
Q

what acid does sr(oh)2 react with to form srso3

A

h2so3

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14
Q

effect of increasing pressure on reaction rate

A
  • increases rate of reaction
  • more molecules per unit volume
  • more frequent collisions
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15
Q

what is le chateliers principle

A

position of equilibrium will shift to minimise the effect of any change in conditions

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16
Q

why do catalysts reduce energy demand

A

-allows reactions to take place at lower temperatures

17
Q

fermentation equation and conditions

A

C6H12O6–> 2C2H5OH + 2CO2

anaerobic
37 degrees
yeast

18
Q

how do NO and CO react in catalytic converter

A

2NO+2CO—>2CO2+N2

19
Q

how does position of equilibrium counteract higher temperature

A

as temperature increases position of equilibrium changes to minimise effect of temperature by absorbing energy

20
Q

how is margarine made out of hydrogen

A

unsaturated vegetable oils and nickel catalyst

21
Q

advantage disadvantage of biodiesel

A

biodiesel renewable
decrease need for fossil fuels
biodiesel more carbon neutral
but forests need to be cut down for land

22
Q

does BaO or MgO have higher pH when added to water

A

BaO

23
Q

ionic compound conductivity solid

A

does not conduct because ions are fixed in lattice and cannot move

24
Q

solid is heated and the gas produced is collected in a gas syringe, how to get accurate result

A
  • heat until syringe stops moving

- wait until gas has cooled before measuring volume

25
Q

apparatus to separate two liquids eg hexane and sodium chlorate

A

separating funnel

26
Q

why does free radical substitution produce many products

A
  • substitution at different positions along chain

- more than one termination step

27
Q

how does catalyst increase rate of reaction

A
  • lower activation energy

- greater proportion of molecules exceed activation energy

28
Q

strontium reaction with water

A

Sr + 2H2O —> Sr(OH)2 + H2

29
Q

how is strontium carbonate converted to strontium oxide

A

heat

30
Q

what colour does cyclohexane change in chlorine

A

orange

31
Q

chlorine reaction with hot concentrated naoh

A

3Cl2 + 6NaOH —> NaClO3 + 5NaCl + 3H2O

32
Q

sodium chlorate vii formula

A

NaClO4

33
Q

why does magnesium have greater bp than sodium

A
  • mg ions have greater charge
  • mg has more outer electrons
  • mg has greater attraction between ions and electrons
34
Q

what is periodicity

A

repeating trend of properties across periods

35
Q

why is experimental enthalpy change different to data book

A
  • non standard conditions
  • heat loss to surroundings
  • incomplete combustion
36
Q

what is average bond enthalpy

A

-average enthalpy change when 1 mol of gaseous covalent bonds is broken

Wrong Exam Qs (41 decks)

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