Formulas For Sem 1 Final Flashcards
What is precision?
How close multiple measurements are to one another
How do you get average deviation?
- Find the mean of your data
- Find deviations from the mean
- Find the average of your deviations
- Quote results as follows:
Mean +- average deviation - Round both to the same number of decimal places as the data
What is accuracy?
How close the experimental results are to the true or a accepted value
What is systematic error and what is it associated with?
It is associated with accuracy and is caused by a consistently present factor
What is paralex error and what is it associated with?
It is associated with accuracy and is an error caused by something the eyes cannot see or by angle of observation
What is random error and what is it associated with?
It is associated with precision and is caused by factors that vary from measurement to measurement
What is the formula for relative uncertainty?
Average deviation/mean value x 100%
What is the formula for Percent error?
l E - T/T l x 100%
What is relative uncertainty associated with?
Random error and precision
What is Percent Error associated with?
It is associated with systematic and paralex errors and accuracy
What is the formula for finding molarity?
Molatrity= c =
number of moles in dissolved substance / volume of solution (in liters)
How do you get from the mass of a sample in grams to the number of moles in the sample?
Mass of the sample in grams/ molar mass of a single atom or molecule = number of moles in the sample
How do you get from the number of moles in the sample to the number of atoms or molecules in the sample?
Number of moles in the sample x avogrado’s # ( 6.022 x 10 )
What is molar mass?
The mass of one mole of an atom or molecule
How do you calculate molar mass?
For atoms it is the same as the atomic mass on the periodic table
For molecule you must add up the molar mass of each atom in the molecule
