Practical Skills Quizizz

What is the function of phenolpthalein in the titration

• to produce a colour solution

• to form and an acidic solution

• for form a base solution

• as an indicator for the acid base titration

What is a standard solution?

• Solution of known concentration

• Solution of known mass

• Solution of known volume

• Solution of known substance

Why the volumetric flask containing a solution prepared is shaken before top up to the mark with water?

• because the solute cannot be dissolved by the solvent

• To avoid the solute from sticking to the flask

• for the particles to be closer before adding solvent

• to form a homogeneous solution

Before starts titrating, ensure no air bubble trap at the tip of the burette, the reason is

• to obtain a more accurate result data

• to ensure no impurities

• air disrupts the flowing of the solution

• To filled the burred with 50.00 mL solution.

Which is not an indicator for an acid base titration?

• methyl orange

• phenolphthaline

• methyl red

• sodium carbonate

These are how to remove air bubble trap at the tip of the burette EXCEPT

• run rapidly few mililiters of the titrant through the tip of the burette.

• rinse the burette with distilled water

• tap gently the side of the burette tip while the solution is flowing.

• grasp the burette and give it a downward jerk while the stop cork is open

Why the pipette and burette should be rinsed with distilled water followed by the solution to be filled?

• plenty of solution available to be used

• does as instructed by teacher but does not know why

• to ensure they are cleaned and to avoid contamination.

• the tiny volume of the solution remaining will change the concentration of the solution filled

Why the pipette is touched once to the side of the conical flask when draining the last bit of the solution?

• to remove the small amount of the solution in the tip which is already accounted in the calibration of the pipette.

• want to drain all the liquid in the pipette

• because of air bubble at the tip of the pipette.

• the small amout of liquid at the tip is not accounted in the calibration of the pipette.

The following are the reason why titrations are repeated 3 or 4 time EXCEPT

• increase the accuracy of the result obtained

• to improve titration skills

• to test the reproducibility of the relults

• to provide statistically valid answer.

Distilled water is used to flush the inside walls of the conical flask and tip of the burette upon reaching the equivalent point. This can be done because

• the amount of substance in conical flask does not change

• the volume of solution in the conical flask does not change

• the colour of the indicator does not change

• the product formed does not change