WorksheetsPractical Skills Quizizz
Total questions: 18
Worksheet time: 9mins
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
Distilled water is used to rinsing down the sides of the flask because of the following EXCEPT
avoid adding more titrant that is necessary to reach endpoint.
to avoid falsely-high volume reading
to make sure all of the titrant which maybe at the top, react with the solution at the bottom.
to make sure the equivalent point is reached faster.
Conical flask is used in the titration instead of beaker because
easier to see colour change
large container
heavier and wont break easily
easily swirled without risk of the content spilling.
why must all solid dissolved with some water in a beaker before transfer the solution into a volumetric flask?
it is easier to transfer solution rather than solid
solid need lots of water to dissolved
to fully dissolve the solid before transferring the solution
the small amount of water will not dissolve the solid
Why a volumetric flask is used in the preparation of the standard solution
volumetric flask can measure unknown concentration
volumetric flask is used to measure exact volume of liquid
solution can be shaken
easier to transfer solution from a beaker to a volumetric flask
How many decimal place does a burette is recorded to?
one decimal place with the last figure either 0 or 5
two decimal places with the last figure either 0 or 5
three decimal places with the last figure either 0 or 5
four decimal places with the last figure either 0 or 5
What is the function of an indicator in the acid-base titration
to signal the endpoint which is roughly equal to the equivalent point
solution cannot change colour by itself
the indicator is is a stable substance
the indicator is inert
All statements is true about titration EXCEPT
titration is an analytical method to determine an unknown concentration based on a known concentration
equivalence point is the point when all the acid has reacted with the base and neither is in excess
equivalent point the point at which which indicator change colour and the titration is stopped.
end point is the point at which indicator chande colour and titration is stopped.
These are how to avoid parallax error when reading a burette
Eye is at the level of the meniscus and read the bottom of the meniscus
Eye is above the level of the meniscus and read the bottom of the meniscus
Eye is below the level of the meniscus and read the bottom of the meniscus
Eye is at the level of the meniscus and read above of the meniscus
