Titration experiment - recap

Why should a buret not be clamped too tightly?

• So it can be easily removed and refilled

• To allow the glass to expand when heated

• To prevent the glass from cracking or breaking

• To ensure the solution does not get blocked

Phenolphthalein is an indicator often used in titrations. In basic solutions, it has a pink color. What does it change into in acidic solutions?

• Red

• Colorless

• Yellow

• Blue

vWhen undertaking a titration, the solution in the buret is usually a standard solution of acid or base. What does the term standard solution refer to?

• An acid or base of known concentration

• A solution of a strong acid or base

• A solution in which no more solid will dissolve

• A neutral solution of fixed volume

Why is a volumetric pipet used to measure out the known volume (aliquot) of a solution?

• To allow a rough volume of a solution to be measured

• Because it is easier to fill a conical flask from a volumetric pipette than from a measuring cylinder

• To allow a very accurate, fixed volume of a solution to be measured

• To prevent the acid or base from reacting with the equipment

When adding a solution from a buret into an Erlenmeyer flask, why is it important that the flask is swirled?

• To prevent the formation of a precipitate

• To increase the rate of reaction

• To ensure the solutions are mixed

• To remove any gas that is formed

Why should a buret always be filled at eye level and never above?

• To allow the buret to be filled while sitting down

• To know when the beaker or measuring cylinder is empty

• To watch the solution move down the buret

• To reduce the risk of splashing acid or base onto the eyes or face

A titration is set up as shown in the diagram. Why is the conical flask placed on a white tile?

• To observe any changes to the turbidity of the solution

• To make it easier to observe any color changes

• To provide a stable base for the conical flask

• To prevent any spilled solution from damaging the lab bench

A student wants to use titration to determine how much acid is needed to neutralize a known volume of base. They set up the experiment as shown. At the start of the experiment, which solution should go into the Erlenmeyer flask and which should be used to fill the buret?

• The acid should go into the Erlenmeyer flask and the base into the buret.

• The base should go into the Erlenmeyer flask and the acid into the buret.

• Water should go into the Erlenmeyer flask and acid into the buret.

• Both the acid and the base should go into the Erlenmeyer flask.

A universal indicator is not normally used as an indicator when performing a titration. Which of the following statements explains why this is the case?

• It changes color over a very narrow pH range.

• It changes color over a very wide pH range.

• It decomposes too quickly.

• It only changes color in acidic solutions.

The equivalence point is:

• The point in a titration where there is a sudden change of color

• The point in a titration when neutralization occurs

• The point in a titration when all titrant is used up in the buret.

• The point in a titration when there is more acid than base.