1. A 25.00 mL sample of 0.20M H2CO3 was titrated with 0.50M NaOH. What volume of NaOH was required to reach the equivalence point? 2. A 10.00 mL sample of vinegar (CH3COOH) was titrated with 18.20 mL of 0.50M NaOH. Calculate the [CH3COOH].

3. In order to standardize a solution of NaOH, 0.18g of oxalic acid, H2C2O4∙2H2O, was dissolved to make 250.00 mL of a solution. A 25.00 mL sample of this solution was titrated against 15.25 mL NaOH. Calculate the [NaOH].

4. Aspirin has the formula C9H8O4. Only one of the H atoms is released when it acts as an acid. An aspirin tablet with a mass of 0.50 g was dissolved in water, and titrated with 18.30 mL of 0.10M NaOH. Calculate the mass of aspirin in the tablet, and then the percent by mass of aspirin in the tablet.