C7 Chemical Calculations With Moles [Paper 1] Flashcards
What is the yield of a reaction?
Mass of product obtained from reaction
What is the theoretical yield of a reaction?
Maximum mass of the product that could have been produced
Why is the actual yield always less than the theoretical yield?
- reaction may be reversible
- some of the product can be lost in separation
- Unexpected side reactions between reactants
What is the percentage yield?
Actual yield as a proportion of the theoretical yield
How is percentage yield calculated?
Actual yield / Theoretical yield x 100
What is atom economy?
Measure of how many atoms of the reactants end up as useful products
Why is high atom economy desirable?
Results in less waste / is more sustainable
How much percentage at an economy calculated?
Mr of useful products / Mr of all products x 100
How can concentration in mol/dm3 be calculated?
Moles of solute / volume (dm3)
What is a titration?
Method used to calculate concentration of an unknown solution
What is the endpoint?
A point which the reaction is complete )when the indicator changes colour) and most substance is an excess
How should solution be added from the burette close to the end point?
Drop a 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 are concordant titres?
Titres within 0.1 cm3 of each other
What volume does one mole of any gas occupy at room temperature and pressure?
24 dm3 or 24,000 cm3
