1. A sample of oxalic acid (H2C2O4, with two acidic protons), of volume 46.56 mL was titrated to the stoichiometric point with 17.06 mL of 0.297 M NaOH(aq). What is the molarity of the oxalic acid? Answer in units of M.
2. What mass of the oxalic acid was in the sample of the solution? Answer in units of g.
To find the molarity of oxalic acid and the mass of oxalic acid in the given sample, we can use the concept of stoichiometry and the equation of the reaction between oxalic acid and NaOH:
H2C2O4(aq) + 2NaOH(aq) → Na2C2O4(aq) + 2H2O(l)
1. To find the molarity of oxalic acid (H2C2O4):
Step 1: Identify the stoichiometric ratio between oxalic acid (H2C2O4) and NaOH.
From the balanced equation, we can see that 1 mole of oxalic acid reacts with 2 moles of NaOH.
Step 2: Calculate the number of moles of NaOH used in the titration:
First, convert the volume of NaOH(aq) to moles:
moles of NaOH = volume (L) × concentration (M)
moles of NaOH = 0.01706 L × 0.297 M
Step 3: Use the stoichiometric ratio to find the moles of oxalic acid:
Since 1 mole of oxalic acid reacts with 2 moles of NaOH,
moles of H2C2O4 = (moles of NaOH) / 2
Step 4: Calculate the molarity of oxalic acid:
Molarity (M) = moles of H2C2O4 / volume of oxalic acid (L)
Molarity (M) = (moles of H2C2O4) / 0.04656 L
2. To find the mass of the oxalic acid in the sample:
Step 5: Calculate the molar mass of oxalic acid:
The molar mass of H2C2O4 = (2 × atomic mass of H) + (2 × atomic mass of C) + (4 × atomic mass of O)
Step 6: Calculate the mass of oxalic acid:
Mass (g) = moles of H2C2O4 × molar mass of H2C2O4
By following these steps, we can find the molarity of oxalic acid and the mass of oxalic acid in the given sample.