Final answer:
To calculate the number of moles of oxalic acid used in the titration, we can use the molarity of sodium hydroxide and the volume of sodium hydroxide used. Plugging in the values, we find that the number of moles of oxalic acid used is 0.01325 mol.
Step-by-step explanation:
To calculate the number of moles of oxalic acid used in the titration, we need to use the balanced equation for the reaction. From the equation, we can see that 2 moles of oxalic acid react with 1 mole of sodium hydroxide. Since the volume of sodium hydroxide used is given as 25 mL, we need to convert it to liters by dividing by 1000. Then, we can use the molarity of sodium hydroxide to calculate the moles of oxalic acid.
Moles of oxalic acid = Molarity of sodium hydroxide x Volume of sodium hydroxide (in liters) x Ratio of moles of oxalic acid to moles of sodium hydroxide.
Plugging in the values, we get:
Moles of oxalic acid = 0.265 M x 0.025 L x (2 mol oxalic acid / 1 mol sodium hydroxide)
Moles of oxalic acid = 0.01325 mol.