# Chemistry 9-1 GCSE equations and formulae

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#1
Guys what are all the AQA chemistry 9-1 equations and formulae that I need to know
0
2 years ago
#2
Same
0
2 years ago
#3
Why has nobody replied to this help me
1
2 years ago
#4
Mass = Mr x mole
Mr = add together the Ar of every atom in the compound
Conc = mass / vol
Conc = moles / vol
Atom economy = useful mass / total mass
Percentage yield = actual yield / expected yield * 100%
RFM of a substance = (Abundance of isotope 1 x Mass of isotope 1) + (Abundance of isotope 2 x Mass of isotope 2)
8
#5
(Original post by Cirsium)
Mass = Mr x mole
Mr = add together the Ar of every atom in the compound
Conc = mass / vol
Conc = moles / vol
Atom economy = useful mass / total mass
Percentage yield = actual yield / expected yield * 100%
RFM of a substance = (Abundance of isotope 1 x Mass of isotope 1) + (Abundance of isotope 2 x Mass of isotope 2)
How do you know what the abundance of the isotope is
0
2 years ago
#6
(Original post by Gurdeepthelegend)
How do you know what the abundance of the isotope is
They'll tell you in the question. So the question would be like what is the Ar of a sample if it contains 90% carbon-12 and 10% carbon-13, and you'd do 0.9 * 12 + 0.1 * 13 = 12.1
0
2 years ago
#7
(Original post by Gurdeepthelegend)
How do you know what the abundance of the isotope is
it will say in the q
0
2 years ago
#8
(Original post by Gurdeepthelegend)
How do you know what the abundance of the isotope is
Abundance = the amount of the element used
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2 years ago
#9
theyll tell you in the question; its the % of how often it occurseg. The most abndant isotope of lithium is 7 Li which accounts for 92.5% f naturally occurring lithium. 3a) calculate the % abundance of the 6 Li answer = 100 - 92.5 = 7.5% 3 b) use this to work out the relative atmic mass of Li to 1 decimal place answer = (7.5 x 6) (92.5 x 7) then / by 100 = 6.925
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2 years ago
#10
Also for Edexcel (at least):

RF value = distance travelled by spot / distance travelled by solvent front.

To get from concentration (mol/dm3) to concentration (g/dm3), you multiply by the RFM.
2
2 years ago
#11
Also mean rate of reaction=quantity of reactants used/time taken
Or mean rate of reaction=quantity of product formed/time taken
0
2 years ago
#12
what does mr and Ar mean
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2 years ago
#13
Ar=Relative Atomic mass
Mr=Relative molecular or formula mass
(Original post by sophieb02)
what does mr and Ar mean
0
1 year ago
#14
(Original post by Cirsium)
Mass = Mr x mole
Mr = add together the Ar of every atom in the compound
Conc = mass / vol
Conc = moles / vol
Atom economy = useful mass / total mass
Percentage yield = actual yield / expected yield * 100%
RFM of a substance = (Abundance of isotope 1 x Mass of isotope 1) + (Abundance of isotope 2 x Mass of isotope 2)
Will they give you the moles value in the exam depending on the question? Plus, with the two concentration equations, what are the units of them both or are they the same?
Last edited by CSeagull08; 1 year ago
0
1 year ago
#15
ur a liya
0
11 months ago
#16
LOL know this is late butmpirical formulaRelative formula massReacting massesMolesDeducing molecular formulaMoleculesConcentrationAbu ndance
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