Calculations Flashcards
how are ratio strengths always expressed?
when calculating ratio strengths, the ……….. is always divided by the ……………..
as 1: (another value)
smaller number, larger number
ppm (parts per million) is equivalent to
mg/L
when calculating concentration and volume questions, which formula is used
C1V1 = C2V2
milli
symbol
10^-3
m
micro
symbol
10^-6
u
nano
symbol
10^-9
n
kilo
symbol
10^3
k
deca
10^1
da
how many pounds make a kg
2.2 pounds
how many feet make a meter
3.3 feet
how many inches make a foot
12 inches
formula to calculate the BMI
mass(kg)/ height(m^2)
molarity SI unit
mol/dm^3 or mol/L
BIDMAS
BODMAS
Brackets, Indices, Division, Multiplication, Addition, Subtraction
Same but with order in place of indices
when calculating ratio strengths, what should be the unit of mass(w)
grams
when calculating ratio strengths, what should be the unit of the volume
mL
what does a 0.9% solution mean
0.9g/100mL
what do these actually mean;
w/v % solution
v/v % solution
w/w % solution
(weight of solute/ volume of solution)*100
(volume of solute/ volume of solution)*100
(weight of solute/ weight of solution)*100
it has to do with paying close attention to something
a tip for when answering formulations questions
when answering these questions, pay close attention to the units of each of the contituents
during complex dilutions, does the amount of the active ingredient/solute change?
no, it remains the same throughout
during compex concetration calculations(which is where the concentration is changed by altering the amount of the active ingredient), does the amount or volume of the diluent ever change
no it does not, it is rather the amount of the active ingredient that changes throughout
