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IGCSE Chemistry > The Mole > Flashcards

Flashcards in The Mole Deck (8)
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1
Q

What is a mole?

A

A mole of a substance is the amount that contains 6.02x1023 units, i.e. the same number of units as the number of carbon atoms in 12g of carbon-12.

2
Q

What is Avogadro’s constant?

A

6.02 x 1023

This is the number of units (atoms/molecules) in one mole of a substance.

3
Q
  • RAM - ?
  • RMM - ?
  • RFM - ?
A
  • RAM - relative atomic mass (also known as Ar)
    • the average mass of the atoms of an element, relative to the mass of an atom of carbon-12
  • RMM - relative molecular mass (also known as Mr)
    • the mass of a molecule, found by adding the Ars of the atoms in it
  • RFM - relative formula mass (also known as Mr)
    • the mass of one formula unit of an ionic compound, found by adding the Ars of the atoms in the formula
4
Q

What volume does one mole of any gas occupy at r.t.p. (room temperature and pressure)?

A

24dm3

24 000 cm3

24 litres

5
Q

What equation relates moles, concentration and volume?

A

amount of solute (mol) = conc. (mol/dm3) x vol. (dm3)

6
Q

What is the empirical formula of a compound?

A

The formula showing the simplest ratio in which atoms combine, found by experiment.

7
Q

What is % yield and how is it calculated?

A

Yield is the amount of product you obtain from a reaction.

%yield = actual mass obatined/calculated mass x 100%

8
Q

What is % purity and how is it calculated?

A

% purity is the percentage of pure product within an impure substance.

% purity of a product = (mass of pure product)/(mass of impure product obtained) x 100%