Quantative Chemistry Flashcards
Law of conservation of mass says…
No atoms are lost or made during a reaction
Alkali metals +water ——>
Metal Hydroxide + hydrogen gas
Percentage by mass formula
Relative atomic mass (Ar)
————————————— X100
Relative Molecular Mass (Mr)
Random error
Cause readings to be spread around the true value due to results varying in an unpredictable way
Systematic Error
Cause readings to differ from the true value by a consistent amount each time
Zero Error
Instrument isn’t calibrated
Uncertainty formula
Range of measurements/2
1 mole
6.02X10^23
What do moles in balanced equations show
The ratio of reactants to products
Moles formula
Moles=mass/mr
% yield formula
Actual yield
——————— X100
Theoretical yield
What is percentage yield
The measure of how much of a product we actually make compared to how much we shoulf
Percentage atom economy formula
Mr of the desired product from equation
———————————————————- X100
Sum of Mr of the reactants from equation
Volume and moles formula
Moles=volume (dm^3)/24
What is concentration
The amount of a substance dissolved in a certain volume of soloution
