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Chemistry 9-1 GCSE equations and formulae

Guys what are all the AQA chemistry 9-1 equations and formulae that I need to know
Reply 1
Avatar for gurlll
gurlll
15
Same
Why has nobody replied to this help me
Reply 3
Avatar for Cirsium
Cirsium
19
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)
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
Reply 5
Avatar for Cirsium
Cirsium
19
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
Original post by Gurdeepthelegend
How do you know what the abundance of the isotope is


it will say in the q
Original post by Gurdeepthelegend
How do you know what the abundance of the isotope is

Abundance = the amount of the element used
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
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.
Also mean rate of reaction=quantity of reactants used/time taken
Or mean rate of reaction=quantity of product formed/time taken
what does mr and Ar mean
Ar=Relative Atomic mass
Mr=Relative molecular or formula mass
Original post by sophieb02
what does mr and Ar mean
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?
(edited 5 years ago)
ur a liya
LOL know this is late but:colone:mpirical formulaRelative formula massReacting massesMolesDeducing molecular formulaMoleculesConcentrationAbundance
and you probably need to know the ones for organic chemistry like alcohols alkenes carboxylic acids etc

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