AQA A LEVEL CHEMISTRY PAPER 2 7401

AQA A LEVEL CHEMISTRY PAPER 2
7401
QUESTIONS AND ANSWERS ALREADY PASSED

◉ the mole of a substance. Answer: is the amount of that substance
that contains as many particles (atoms or molecules or ions) as
there are atoms of C¹² in 12g of C¹². (or Avogadro's constant)


◉ Carbonate Formula. Answer: CO3 2-


◉ Sulfate Formula. Answer: SO4 2-


◉ Hydroxide Formula. Answer: OH -1


◉ Nitrate Formula. Answer: NO3 -1


◉ Ammonium Formula. Answer: NH4 +1


◉ Working Out Ionic Equations. Answer: 1 ) Write out the balanced
equation with state symbols
2 ) Separate compounds into ions
3 ) Remove parts that are on both sides of the equation

, 4 ) Write out ionic equation (with state symbols)


◉ Calculating Moles from Mass. Answer: Moles = Mass/Mr


◉ Relative molecular mass. Answer: The weighted mean mass of a
molecule compared with one-twelfth of the mass of an atom of
carbon-12.


◉ Relative isotopic mass. Answer: The mass of an atom of an isotope
compared with one-twelfth of the mass of an atom of carbon-12.


◉ Relative formula mass. Answer: The weighted mean mass of the
formula unit of a compound compared with one-twelfth of the mass
of an atom of carbon-12.
(for ionic compounds)


◉ Using the Avogadro Constant. Answer: Moles = Number of
particles/Avogadro Constant


◉ Using Balanced Equations Quantitavely. Answer: 1 ) Calculate the
moles of the reactant you are given the mass of (mass/Mr)
2 ) Use the balancing numbers to calculate the moles of the
substance asked about
3 ) Multiply the moles by the Mr to find the mass