Calculate the molarity of an aqueous NaOH solution if 32.00ml of it is required to titrate .6789g of oxalic acid to a phenophthalein end-point. the balanced chemical equation is
H2C2O4 + 2NaOH ---> Na2C2O4 + 2H2O
I worked this for someone last night.
mols oxalic acid = grams/molar mass.
Use the coefficients in the balanced equation to convert mols H2C2O4 to mols NaOH.
M NaOH = mols NaOH/L NaOH
To calculate the molarity of the NaOH solution, we need to use the balanced chemical equation and the given data.
1. Find the number of moles of oxalic acid (H2C2O4) using its molar mass.
- Molar mass of H2C2O4 = 2 * (1.01 g/mol) + 2 * (12.01 g/mol) + 4 * (16.00 g/mol) = 90.034 g/mol
- moles of H2C2O4 = mass of H2C2O4 / molar mass of H2C2O4 = 0.6789 g / 90.034 g/mol
2. Use the stoichiometric ratio from the balanced chemical equation to determine the number of moles of NaOH.
- According to the balanced equation, 1 mole of H2C2O4 reacts with 2 moles of NaOH.
- moles of NaOH = moles of H2C2O4 * (2 moles NaOH / 1 mole H2C2O4)
3. Calculate the molarity of the NaOH solution using the volume of the solution used in the titration.
- Molarity (M) = moles of NaOH / volume of NaOH solution (in L)
- Convert the volume from mL to L: volume of NaOH solution = 32.00 mL / 1000 (conversion to L)
4. Substitute the values into the formula and calculate the molarity.
- Molarity (M) = moles of NaOH / volume of NaOH solution
By following these steps, you should be able to calculate the molarity of the NaOH solution.