C3 Flashcards
What’s the law of conservation of mass?
No atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants
What’s the relative formula mass (Mr)?
Sum of the relative atomic masses
Why do some reactions may appear to involve a change in mass?
A reactant or product is a gas, and its mass has not been taken into account.
What’s the Avogadro constant?
6.02 x 10²³ per mole.
What’s a limiting reactant?
The reactant that is completely used up
Equation for moles
Moles = mass /Mr
Equation for concentration
Concentration = mass or moles / volume
What is 1000cm3 in g/dm3?
1g/dm3
Equation for percentage yield
Mass of product actually made / Maximum theoretical mass of product ×100
What is atom economy?
The atom economy is a measure of the amount of starting materials that end up as useful products.
Equation for atom economy
Relative formula mass of desired product from equation/Sum of relative formula masses of all reactants from equation ×100
Equation for concentration in g/dm3
g/dm3 = mol/dm3 X Mr
What is the volume of one mole of gas at room temperature?
The volume of one mole of any gas at room temperature and pressure (20oC and 1 atmosphere pressure) is 24 dm3.
