Quantitive Chemistry Flashcards
What is the equation to calculate the % mass of an element in a compound?
Ar x number of atoms of that element / Mr of the compound x 100
Equation to calculate moles
Mass in g / Mr
State the avogadro constant
6.02 x 10^23
You will never get a 100% yield, why is that?
1) Not all reactants make a product
2) There might be side reactions
3) You lose some product when you separate it from the reaction mixtures
When do reactions stop?
When a reactant is used up
How do you work out volume of gas?
Mass of gas / Mr of gas x 24
What are the two equations for concentration?
Concentration = mass of solute / volume of solvent Concentration = number of moles of solute / volume of solvent
Higher atom economy is better for profits and environment explain this.
The waste will have to go somewhere
Raw materials are expensive to buy
What is the atom economy equation?
Relative formula of desired products / relative formula mass of all products
What is the percentage yield?
Mass of product actually made / maximum theoretical mass of products x 100
Yields are always less than 100%, give reasons for this.
Not all reactants make a product
There might be a side reaction
You lose some product when you separate it from the reaction mixture
