Determine the pH of a solution of HF at each of the following concentrations?
HF is a weak acid so you will need to do an ICE table
HF + H2O —-> H3O+ + F-
0.300
-x………………………+x…..+x
0.300-x……………x……..x
x^2/(0.300-x) = 3.5×10^-4
Suppose 0.300-x ~ 0.300
-registration[X] find the pH
if x / 0.300 is less than 5%, your guess is good. Otherwise you can’t assume x is small and you’ll have to solve the quadratic equation.
This will let you know how to fix the issues.
Ph of Hf
1) 3.5E-4=x2/(.3-x)
—ice sheet formation equation
x=[H+]=.010073
-log.010073 = 1.99684
pH = 2
2) pH=2.39
3) pH=2.55
in b and c you cannot make this assumption because the actual concentrations produced are more than 5% of what the error allows when using the small number approximation
would you happen to know how to do the tampons in the medicine problem??
pH= -log[concentration]
pH= -log[0.3M]=0.52
pH= -log[5.10 x 10^-2]= 1.29
pH= -log[2.60 x 10^-2]= 1.59
pH=-log[3.5 x 10^-4]= 3.46
These are all acidic because they are below 7. Anything above 7 is basic.
x is smaller in the first.