C4 Quantitive Chemistry Flashcards
Atom economy
Measure of efficiency of a chemical reaction
How to calculate a titre
The values are added together and divided by the readings
How concentration of a solution can be changed
Can be increased by dissolving more solute in a given volume of solution
Why using reactions with high atom economy is important
Uses fewer natural resources and less waste
Theoretical yield
Amounts of products calculated from the complete reaction of the limiting reagent
Actual yield
The quantity of a product found to be formed in a chemical reaction
Why chemical equations must be balanced
To abide by the law of conservation of mass
Effect of a limiting reactant on the amount of product made
No more product can form when the limiting reactant is all used up
How the volume of gas would change when temperature or pressure was changed
If the container holding a gas is flexible the volume will increase
How to caclulate atom economy
Mass of desired products
____________________________ x 100
mass of products
How accuracy can be improved in a titration
Titrate less sample
How an indicator can be used to determine the end point
Helps us to visually spot the equivalence point in an acid-base titration
Why is actual yield is often lower than theoretical yield
Due to loss in the process or inefficiency of the chemical reaction
Why percentage yield can never be above 100%
Could be because not all of the reactants are used in the reaction
How precise results are obtained in a titration
Experimental error is approximately 0.2%
