Now, lets say you're performing a titration of some acetic acid. You have reason to doubt that the grocery store is selling your vinegar at the concentration listed on the label. The label says the contents are 1M acetic acid.
You begin performing the titration on 5mL of the acetic acid sample with 0.1M NaOH. You perform the titration and find that your indicator (phenolphthalein) turns the slightest shade of pink and determine you've added 40mL of the 0.1M NaOH.
What is the concentration of the acetic acid purchased from the grocery?
a) 1.2 M
b) 2.5 M
c) 0.5 M
d) 0.8 M
To determine the concentration of acetic acid in the sample, we can use the equation:
M1V1 = M2V2
Where M1 is the initial concentration of acetic acid, V1 is the initial volume of acetic acid, M2 is the concentration of NaOH, and V2 is the volume of NaOH needed for neutralization.
Plugging in the values we have:
(1M)(5mL) = (0.1M)(40mL)
5 = 4
Therefore, the concentration of the acetic acid purchased from the grocery store is 0.8 M.
d) 0.8 M