What is the molarity of an unknown acid if 40.5 ml of the acid can be titrated to an end point by 20.5 ml of 0.2250 M NaOH?
We can't know if we don't know if the acid is monoprotic, diprotic, or triprotic. So which kind of acid is it and which equivalence point did we reach? If it's monoprotic you can use the simple equation of
mL x M = mL x M.
0.114 M
To find the molarity of the unknown acid, we can use the equation: M(acid) * V(acid) = M(base) * V(base)
Where:
- M(acid) is the molarity of the acid (what we want to find)
- V(acid) is the volume of the acid used in the titration (40.5 ml)
- M(base) is the molarity of the NaOH solution (0.2250 M)
- V(base) is the volume of the NaOH solution used in the titration (20.5 ml)
Now we can substitute the values into the equation and solve for M(acid):
M(acid) * 40.5 ml = 0.2250 M * 20.5 ml
M(acid) = (0.2250 M * 20.5 ml) / 40.5 ml
M(acid) = 0.2297 M
Therefore, the molarity of the unknown acid is 0.2297 M.
To determine the molarity of the unknown acid, you can use the concept of stoichiometry and the balanced equation of the reaction between the acid and NaOH. Here's how you can get the answer:
1. Start by writing the balanced equation for the reaction between the acid and NaOH:
Acid + NaOH ---> Salt + Water
2. From the balanced equation, you can see that the stoichiometric ratio between the acid and NaOH is 1:1. This means that one mole of acid reacts with one mole of NaOH.
3. Calculate the number of moles of NaOH used in the titration using the given volume and molarity. Use the equation:
Moles of NaOH = Volume of NaOH used (in liters) * Molarity of NaOH
Moles of NaOH = 20.5 ml * (1 L / 1000 ml) * 0.2250 mol/L
4. Convert the volume of the acid used in the titration to liters:
Volume of Acid = 40.5 ml * (1 L / 1000 ml)
5. Since the stoichiometric ratio between the acid and NaOH is 1:1, the number of moles of the acid present is equal to the number of moles of NaOH used in the titration.
Moles of Acid = Moles of NaOH
6. Calculate the molarity of the unknown acid using the equation:
Molarity of Acid = Moles of Acid / Volume of Acid
Plug in the values you calculated into this equation to find the molarity of the unknown acid.