Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A Level Chemistry > Module 2 - Amount of Substance > Flashcards

Module 2 - Amount of Substance Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

define relative atomic mass

A

weighted mean mass of an atom relative to 1/12th of the mass of one atom of carbon 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define relative formula mass

A

term used when working out the calculation for compounds with giant structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

examples of giant structures for relative formula mass

A

giant ionic, giant covalent, giant metallic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define relative molecular mass

A

term used when working out the calculation for compounds that are simple molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

equation for percentage of an element

A

number of atoms of element x relative atomic mass of element / relative formula mass of compound x100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

define molar mass

A

the mass per mol of a substance in g mol^-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the mass of one mole equal

A

the ar of that substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

define amount of substance

A

chemists use amount of substance as a means of counting the number of particles in a substance. its unit is the mole (mol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

define avogadros constant

A

6.02 x 10^23. the number of atoms per mole of carbon 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

equation for number of atoms/ions/molecules

A

moles x 6.02x10^23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

equation for number of mols

A

mass (g) / molar mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

units for molar mass

A

g mol -1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

define molecular formula

A

the number and type of atoms in each element of a molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define empirical formula

A

shows the simplest whole number ratio of atoms of each element in a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

steps to calculate empirical formula

A
  • calculate number of moles
  • divide number of moles by smallest value for a ratio
  • adjust to make ratios whole numbers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define water of crystallisation

A

water molecules that are bonded into a crystalline structure of a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does heated hydrated copper sulfate form

A

anhydrous copper sulfate + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

symbol equation for heating copper sulfate

A

CuSO4 . 5H2O -> CuSO4 + 5H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

define hydrated

A

a crystallised compound containing water molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

define anhydrous

A

contains no waters of crystallisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

method for calculating amount of water

A

-weigh the crucible
-add a known amount of hydrated salt
-weigh the crucible and hydrated salt together
-heat the hydrated salt strongly for a few minutes
-weigh and heat the sample until the mass stays constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

assumptions in calculating amount of water

A

-assuming all water has been lost by heating to constant mass
-when heating the salt its not breaking down further to other compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

define molar gas volume

A

the volume per mole of gas molecules at the stated temperature and pressure (RTP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

room temperature

A

25 degrees

25
Q

room pressure

A

101 kPa

26
Q

what is the volume of a gas at RTP

A

1 mole of gas is 24.0dm^3

27
Q

equation for volume of a gas in dm^3

A

moles = volume (dm3) / 24

28
Q

equation for volume of a gas in cm^3

A

moles = volume (cm3) / 24,000

29
Q

ideal gas equation

A

pV = nRT

30
Q

degrees to kelvin conversion

A

add 273

31
Q

kPa to Pa

A

add x10^3 on the end

32
Q

cm^3 to m^3

A

add x10^-6 on the end

33
Q

dm^3 to m^3

A

add x10^-3 on the end

34
Q

ideal gas equation in words

A

volume x pressure = amount of gas x ideal gas constant x temperature

35
Q

volume units in ideal gas equation

A

m^3

36
Q

pressure units in ideal gas equation

A

Pa

37
Q

amount of gas units in ideal gas equation

A

mol

38
Q

temperature units in ideal gas equation

A

K

39
Q

define stoichiometry

A

-the ratio, of the amount in moles, of each substance in a chemical reaction

40
Q

steps for stoichiometry calculation

A

-write mr of substance known and unknown
-calculate moles of known
-ratio for moles of unknown
-work out question

41
Q

steps for limiting reactant calculation

A

-calculate moles for both reactants
-do a ratio of how much you need for each one
-use the limiting reactant moles to work out the rest of the question

42
Q

units for concentration

A

mol dm^-3

43
Q

equation for number of moles (concentration)

A

volume x concentration / 1000

44
Q

units of volume in concentration equation

A

cm^3

45
Q

why do you divide by 1000 in the concentration equation

A

to convert volume to dm^3

46
Q

what is percentage yield

A

the amount of product made from the starting materials

47
Q

why does no reaction ever have 100% yield

A

-the reaction may have not gone to completion
-side reactions may have occurred
-purification of the product may have resulted in loss of product

48
Q

percentage yield equation

A

actual moles/ theoretical moles x 100

49
Q

percentage yield calculation steps

A

-workout mr or the reactant and product you have a mass for
-work out the actual moles (mass of the product)
-workout the theoretical moles (mass of the reactant-> ratio)
-put in equation

50
Q

what happens in an ideal reaction

A

-all reactant atoms end up within the useful product molecule -no waste is produced

51
Q

which reactions have low atom economy

A

-inefficient, wasteful reactions

52
Q

which reactions have high atom economy

A

-efficient processes have high atom economy

53
Q

why are high atom economy reactions important

A

-sustainable development
-conserve natural resources
-create less waste

54
Q

atom economy equation

A

sum of molar masses of all desired products / sum of molar masses of all products x100

55
Q

what is atom economy a measure of

A

-the proportion of reactant included in the final useful product

56
Q

how are atom economy and percentage yield linked in a reaction

A

a reaction can have a
-high percentage yield
-low atom economy

57
Q

what is the percentage atom economy if a reaction has 1 product

A

100%

58
Q

define mole

A

the amount of any substance containing as many particles as there are carbon atoms in 12g of carbon 12 (6.02x10^23 particles)

59
Q

which reactant do you use for theoretical moles in percentage yield if there are multiple

A

the limiting reactant

A Level Chemistry (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions