AQA GCSE CHEMISTRY QUANTITATIVE
CHEMISTRY EXAM WITH VERIFIED
ANSWERS AREADY GRADED A+.
What does low atom economy mean - CorreCt Answers -Low atom
economy; uses up resources quickly. Create lot's of waste = big problem, as
needs to be disposed of safely. These reactions are usually unsustainable,
due to being unprofitable.
One way around this is to find a use for the 'by-products', this is more
economical than just disposing of them.
How can magnesium sulfate be synthesised - CorreCt Answers -1
Magnesium and sulfuric acid
Mg + H2SO4 MgSO4 + H2
2 Magnesium oxide and sulfuric acid
MgO + H2SO4 MgSO4 + H2O
3 Magnesium hydroxide and sulfuric acid
Mg(OH)2 + H2SO4 MgSO4 + 2 H2O
4 Magnesium carbonate and sulfuric acid
MgCO3 + H2SO4 MgSO4 + H2O + CO2
How are moles concentration and volume linked? - CorreCt Answers -
moles = concentration (mol/dm3) x volume (dm3)
How do you convert from mol to grams - CorreCt Answers -Multiply by
relative formula mads
, How do you convert from mol/dm3 to g/dm3 - CorreCt Answers -multiply
by Mr
What is the volume of a mole of a gas? - CorreCt Answers -At the same
temperature and pressure, equal number of moles of any gas will occupy
the same volume.
At room temperature and pressure (r.t.p = 20 ⁰ C & 1 atm), one mole of any
gas will occupy a volume of 24 dm3.
How do you find the volume of a gas in dm3? - CorreCt Answers -Mass/ mr
x 24 or moles x 24What is the law of conservation of mass? - CorreCt
Answers -matter cannot be created or destroyed
Why may there be a change in mass? - CorreCt Answers -Some reactions
may appear to involve a change in mass but this can usually be explained
because a reactant or product is a gas and its mass has not been taken into
account
What is the relative atomic mass? - CorreCt Answers -Relative Atom Mass
(Ar) of an element is the average mass of all the atoms of the element
relative to the mass of an atom of carbon- which is exactly 12.
What is the relative formula mass? - CorreCt Answers -The relative formula
mass (Mr) of a compound is the sum of the relative atomic masses of all the
atoms in the formula.
How do you work out relative formula mass with brackets? - CorreCt
Answers -Work out what is inside the bracket
CHEMISTRY EXAM WITH VERIFIED
ANSWERS AREADY GRADED A+.
What does low atom economy mean - CorreCt Answers -Low atom
economy; uses up resources quickly. Create lot's of waste = big problem, as
needs to be disposed of safely. These reactions are usually unsustainable,
due to being unprofitable.
One way around this is to find a use for the 'by-products', this is more
economical than just disposing of them.
How can magnesium sulfate be synthesised - CorreCt Answers -1
Magnesium and sulfuric acid
Mg + H2SO4 MgSO4 + H2
2 Magnesium oxide and sulfuric acid
MgO + H2SO4 MgSO4 + H2O
3 Magnesium hydroxide and sulfuric acid
Mg(OH)2 + H2SO4 MgSO4 + 2 H2O
4 Magnesium carbonate and sulfuric acid
MgCO3 + H2SO4 MgSO4 + H2O + CO2
How are moles concentration and volume linked? - CorreCt Answers -
moles = concentration (mol/dm3) x volume (dm3)
How do you convert from mol to grams - CorreCt Answers -Multiply by
relative formula mads
, How do you convert from mol/dm3 to g/dm3 - CorreCt Answers -multiply
by Mr
What is the volume of a mole of a gas? - CorreCt Answers -At the same
temperature and pressure, equal number of moles of any gas will occupy
the same volume.
At room temperature and pressure (r.t.p = 20 ⁰ C & 1 atm), one mole of any
gas will occupy a volume of 24 dm3.
How do you find the volume of a gas in dm3? - CorreCt Answers -Mass/ mr
x 24 or moles x 24What is the law of conservation of mass? - CorreCt
Answers -matter cannot be created or destroyed
Why may there be a change in mass? - CorreCt Answers -Some reactions
may appear to involve a change in mass but this can usually be explained
because a reactant or product is a gas and its mass has not been taken into
account
What is the relative atomic mass? - CorreCt Answers -Relative Atom Mass
(Ar) of an element is the average mass of all the atoms of the element
relative to the mass of an atom of carbon- which is exactly 12.
What is the relative formula mass? - CorreCt Answers -The relative formula
mass (Mr) of a compound is the sum of the relative atomic masses of all the
atoms in the formula.
How do you work out relative formula mass with brackets? - CorreCt
Answers -Work out what is inside the bracket
