3 Amount of substance Flashcards
What is the Avagrado constant?
6.02*10^23 mol-1
What is the formula for amount (n)?
amount= mass/molar mass n= m/M
What is relative molecular mass?
The weighted mean mass of a molecule of a compound compared with 1/12th of the mass of an atom of carbon-12.
What is relative formula mass?
The weighted mean mass of the formula unit of a compound compared with 1/12th of the mass of an atom of carbon-12.
What is the formula for amount (n) in solution?
n= c*V
What is the molar gas volume?
The volume per mole of gas molecules at a stated temperature and pressure.
At RTP (room temperature), the molar gas volume= 24dm^3
= 24000cm^3
What is the formula for amount (n) in gas?
amount= volume/molar gas volume n= v (dm)/24 n= v (cm)/24000
What are the following assumptions for the molecules making up an ideal gas?
- Random motions
- Elastic collisions
- Negligible size
- No intermolecular forces
What is the ideal gas equation?
pV= nRT R= ideal gas constant= 8.31Jmol-1K K= temperature starting at absolute zero (-273 degrees)
What is theoretical yield?
Theoretical yield is the maximum possible amount of product.
Why is it difficult to achieve theoretical yield?
- The reaction may have not gone to completion.
- Other reactions may have taken place alongside the main reaction
- Purification of the product may result in loss of some product.
What is actual yield?
Actual yield is the amount of product obtained from a reaction.
What is the formula for percentage yield?
(Actual yield/Theoretical yield) *100
What is the limiting reagent?
The reactant that is not in excess, which will be used up first and stop the reaction.
What is the formula for atom economy?
(sum of Mr of desired products/sum of Mr of all products)*100
