finishing touches - stuff to know that i didnt know Flashcards

1
Q

how does phosphorus exist

A

as P4 molecules

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2
Q

how does sulfur exist

A

as s8 molecules

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3
Q

the first 20 elements in the periodic table are catagorised according to bonding and structure. what are the elements catagorised into metallic?

A
  • lithium
  • beryllium
  • sodium
  • magnesium
  • aluminium
  • potassium
  • calcium
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4
Q

the first 20 elements in the periodic table are categorised according to bonding and structure. which elements are categorised into covalent molecular?

A
  • H2
  • N2
  • O2
  • F2
  • Cl2
  • P4
  • S8
  • fullerenes eg C60
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5
Q

the first 20 elements in the periodic table are categorised according to bonding and structure. which elements are categorised into covalent network?

A
  • Boron
  • Carbon - diamond, graphite
  • Silicon
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6
Q

the first 20 elements in the periodic table are categorised according to bonding and structure. whiche elements are categorised into monatomic?

A

noble gases

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7
Q

what are the steps to balancing a redox equation

A
  • balance the main element
  • add water to balance oxygen atoms
  • add hydrogen ions to balance hydrogen atoms
  • add electrons to the same side as the hydrogen ions to balance the charge
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8
Q

what are strong reducing agents

A

carbon monoxide gas

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9
Q

what are strong oxidising agents

A
  • hydrogen peroxide (H2O2)

- dichromate (Cr2O7) and permangenate (MnO4) group ions -

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10
Q

what does the oxidation of edible oils result in

A

rancidity

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11
Q

what does distillation do

A

separates chemicals with different boiling points

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12
Q

what does chromatography do

A

separates chemicals due to difference in polarity or size

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13
Q

what are factors to control in chromatography

A

the temperature of the column because increasing the temperature would increase the kinetic energy of the particles and they would pass through the column more quickly.
size because smaller molecules will pass through the column more quickly than larger molecules

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14
Q

describe how to prepare a burette for titration

A
  • rinse with whatever solution is being used
  • fill buretted above the scale with the solution
  • remove filter funnel
  • open tap to drain some of the solution to ensure there are no air bubbles
  • reading should be taken from the bottom of the meniscus
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15
Q

what is the reduction reaction in benedicts solution

A

Cu2- + e- –> Cu+

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16
Q

what is the reduction reaction in tollens reagent

A

Ag+ + e- –> Ag2+

17
Q

what is the reduction reaction in acidified dichromate

A

Cr207 2- + 14H+ + 6e- –> 2Cr3+ + 7H2O

18
Q

what is the reduction reaction in acidified permangenate

A

MnO4- +8H+ +5e- → Mn2+ + 4H2O

19
Q

why should one of the reactants always be in excess

A

to ensure that all of the limiting reactant is used up - for instance an ecess of sodium hydroxide allows to ensure that all chlorine is used up and prevents it from being released