AQA A-Level Chemistry | Amount of Substance Study Guide & Exam Questions
Calculating empirical formula 1. % by mass
2. Divided by Ar
3. Divide by smallest
Calculate molecular formula Relative molecular mass divided by relative mass of empirical formula
equation for amount of moles (Avogadro constant) amount of moles = number of particles / Avogadro constant
4 reasons for lack of 100% percentage yield? loss by mechanical transfer, loss during separating technique, unwanted side
reactions, reaction not complete
units 1cm3 - 1ml
1dm3 - 1l
1dm3 - 1000cm3
what is titration an example of? volumetric analysis
2 reasons why conical flasks are used in titration? 1. can swirl reactant easily
2. sloped sides ensure solution can not spill out
what is the dilution factor? how is it calculated? the amount the original solution is diluted by.
new total volume/ volume of original solution added
what is the dilution factor of 25cm3 to 250cm3 10
what is important about the first titre? it should be rough and bigger than the two accurate titrations
what is a standard solution? a solution of known concentration
what should values be recorded to in a titration? 0.05cm3
what should two accurate titre values be? within 0.10cm3 of each other
how to convert from gdm-3 to moldm-3? gdm-3 multiplied by Mr
, AQA A-Level Chemistry | Amount of Substance Study Guide & Exam Questions
equation for percentage error? error of equipment/volume of solution
what kind of titration is phenolphthalein used for? a strong and weak acid-strong base
what is the colour of phenolphthalein in 3 solutions? acid - colourless
neutral - colourless
alkaline - pink
what is the colour of methyl orange in 3 solutions? acid - red
neutral - orange
alkaline - yellow
which solution goes in the conical flask? alkali
which solution goes in the burette? acid
what is the molar volume? 1 mole of a gas occupies a volume of 24dm3 at room temperature and pressure
equation for moles (gas) moles = volume / 24dm3
what three factors does the ideal gas equation relate? 1. as pressure increases, the volume of a gas decreases
2. as temperature increases, the volume of a gas increases
3. the amount of gas in moles is directly proportional to its volume
Ideal Gas Eqaution pV = nRT
How do you convert Celsius to Kelvin? K = C + 273
what is volume measured in ideal gas equation? m3
how to convert from m3, dm3, cm3 1m3 = 1000dm3 = 1000000cm3
what does percentage yield not take into account? any waste products
Calculating empirical formula 1. % by mass
2. Divided by Ar
3. Divide by smallest
Calculate molecular formula Relative molecular mass divided by relative mass of empirical formula
equation for amount of moles (Avogadro constant) amount of moles = number of particles / Avogadro constant
4 reasons for lack of 100% percentage yield? loss by mechanical transfer, loss during separating technique, unwanted side
reactions, reaction not complete
units 1cm3 - 1ml
1dm3 - 1l
1dm3 - 1000cm3
what is titration an example of? volumetric analysis
2 reasons why conical flasks are used in titration? 1. can swirl reactant easily
2. sloped sides ensure solution can not spill out
what is the dilution factor? how is it calculated? the amount the original solution is diluted by.
new total volume/ volume of original solution added
what is the dilution factor of 25cm3 to 250cm3 10
what is important about the first titre? it should be rough and bigger than the two accurate titrations
what is a standard solution? a solution of known concentration
what should values be recorded to in a titration? 0.05cm3
what should two accurate titre values be? within 0.10cm3 of each other
how to convert from gdm-3 to moldm-3? gdm-3 multiplied by Mr
, AQA A-Level Chemistry | Amount of Substance Study Guide & Exam Questions
equation for percentage error? error of equipment/volume of solution
what kind of titration is phenolphthalein used for? a strong and weak acid-strong base
what is the colour of phenolphthalein in 3 solutions? acid - colourless
neutral - colourless
alkaline - pink
what is the colour of methyl orange in 3 solutions? acid - red
neutral - orange
alkaline - yellow
which solution goes in the conical flask? alkali
which solution goes in the burette? acid
what is the molar volume? 1 mole of a gas occupies a volume of 24dm3 at room temperature and pressure
equation for moles (gas) moles = volume / 24dm3
what three factors does the ideal gas equation relate? 1. as pressure increases, the volume of a gas decreases
2. as temperature increases, the volume of a gas increases
3. the amount of gas in moles is directly proportional to its volume
Ideal Gas Eqaution pV = nRT
How do you convert Celsius to Kelvin? K = C + 273
what is volume measured in ideal gas equation? m3
how to convert from m3, dm3, cm3 1m3 = 1000dm3 = 1000000cm3
what does percentage yield not take into account? any waste products
