Activity 6-I | Standardization of NaOH

Molarity

A concentration unit that is equal to moles of solute per liter of solution

Neutralization reaction

A reaction in which an acid and base form a salt and water

Standard solution

A solution that has an accurately known concentration of a known substance

Titration

A method in which the concentration of an unknown solution is determined by measuring the volume of the unknown solution required to react completely with a known mass or volume of another compound or solution

Indicator

A chemical that changes color due to a chemical change, such as a change in acid or base concentration

Equivalence point

The point in a titration when the exact number of moles of titrant required to react completely with the unknown have been added (i.e. the point at which the moles of titrant added equal the moles of unknown)

Which of the following is the balanced chemical equation for the reaction that will occur during the titration in this activity?

2 NaOH(aq) + H₂C₂O₄(aq) → Na₂C₂O₄(aq) + 2 H₂O(l)

When you are ready to begin the titration that is described in the procedure, in which piece of glassware will the solution of NaOH be located?

Beaker

When you are ready to begin the titration that is described in the procedure, in which piece of glassware will the solution of oxalic acid be located?

Erlenmeyer flask

Which of the following properties of the oxalic acid sample will be known at the beginning of the titration?

Mass of oxalic acid that was dissolved

Which of the following is used as the primary standard in this titration?

Oxalic acid

Why can't NaOH(s) be used as a primary standard?

It is hygroscopic

Hygroscopic compound

A compound that tends to pick up water from the atmosphere

Primary standard

A compound that is available in a very pure form, is not hygroscopic, is soluble in water, and has a reasonably high molar mass; can be accurately weighed