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How can concentration in mol / dm³ be calculated?
Concentration = moles / volume (dm³)
What is a mole?
A mole is a mass of a substance that contains 6.02 × 10²³ particles.
Give the value for Avogadro's constant.
6.02 x 10²³
What is a titration?
A titration is a method used to determine the concentration of an unknown solution.
What is the end-point?
The point at which the reaction is complete, indicated by a color change.
Which formula is used to calculate the number of moles from mass and M?
moles = mass / M.
Which formula is used to calculate the mass of a substance from number of moles and M?
mass = moles x M.
How should solution be added from the burette to reach the end point?
Add drop by drop, swirling in between.
Why is a white tile used in titration?
To see the colour change better.
What is a titre?
Volume of solution added from the burette
What is a limiting reactant?
The reactant that is completely used up in a chemical reaction.
What volume does one mole of any gas occupy at room temperature and pressure?
24 dm³ or 24000 cm³.
What is a unit for concentration?
g/dm³ or mol/dm³.
Which formula is used to calculate concentration from mass and volume?
concentration (g/dm³) = mass / volume (dm³).
Which formula is used to calculate volume from concentration and mass?
volume (dm³) = mass / concentration (g/dm³).
Which formula is used to calculate mass from concentration and volume?
mass (g) = concentration (g/dm³) x volume (dm³).
How can you convert a volume reading in cm³ to dm³?
Divide by 1000.
If the amount of solute in a solution is increased, what happens to its concentration?
The concentration increases.
If the volume of water in a solution is increased, what happens to its concentration?
The concentration decreases.
What is the yield of a reaction?
The mass of product obtained from the reaction.
What is the theoretical yield of a reaction?
The maximum mass of the product that could have been produced.
Why is the actual yield always less than the theoretical yield?
Some of the product can be lost on separation
Unexpected side reactions between reactants
Reactions may be reversible
What is the percentage yield?
The actual yield as a proportion of the theoretical yield.
How is percentage yield calculated?
(actual yield / theoretical yield) x 100.
What is atom economy?
A measure of how many atoms of the reactants end up as useful products.
Why is a high atom economy desirable?
It results in less waste and is more sustainable.
How is percentage atom economy calculated?
(M of useful product / M of all products) x 100.
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