Unit 2 Learning Aim A L3 Applied Science Year 12
Assignment 2A – Calibrations
Introduction:
In this assignment I will be discussing and explaining the calibration of equipment
and how it helped my results with accuracy. I will be explaining the preparation of
Na2CO3 , standardisation of HCl and the method of titration with NaOH and HCl. I
will be finding the concentration and moles of NaOH for both of my titration methods
(indicators and pH metres). I will be explaining how I did the titration using pH
metres and indicators , discussing the difference between the two while comparing
my results with peers. I will be identifying errors that can be made , how to avoid
them and how these errors can affect the accuracy of results. I will also be plotting a
curve for the pH metre titration and using the equivalence point to find the
concentration of NaOH.
Calibration- checking a measuring instrument to check if it is accurate.
Colorimetry- measurement of colour replacing the numeracy system.
Titration is where the solution has a known concentration and determines the
concentration of an unknown acid or alkali solutions using equipment and glassware.
Set up for titration
Firstly, the apparatus should
be set up in the labelled
image.
Reasons of importance for
the accuracy of the
experiment using certain
equipment:
The burette clamp is to make
sure the burette doesn’t move.
The volumetric flasks
measure volumes to a given
mark giving high accuracy as
they are specifically designed
to hold a certain amount of
liquid , this ensures that the volume of liquid during the titration is known precisely
.
1
,Unit 2 Learning Aim A L3 Applied Science Year 12
A Burette is used to measure and distribute amounts of either liquid or gas, the
calibration of a burette reduces the number of systematic errors in titration by
ensuring it gives accurate measurements of the dispensed liquid.
Safety pipette filler is made of rubber and is used to draw liquid into pipettes, this
reduces the risk of pipetting when handling toxic, corrosive or bad-smelling liquids.
pH meter is a piece of equipment used to measure the acidity or alkalinity of a liquid.
They are good for accuracy as human error can't affect the accuracy of their
readings.
pH probe - an instrument used to measure hydrogen ion activity in a solution.
The ph metre has 2 electrodes measuring the solutions' hydrogen ion activity. The
ions exchange a voltage and that is measured by the ph metre.
A test probe is a device used to connect electronic test equipment to a device under
a test.
The need to calibrate pH metres is for accuracy and to make sure your
measurements are reliable.
Other ways to measure pH:
● The indicator method, where an indicator solution turns a certain colour to
know what pH it is.
● A red and blue litmus paper, where if the solution turns blue on the red litmus
paper it means it's an acid, and if the solution turns red on the blue litmus
paper.
● pH paper which turns a specific colour for each pH value, shown in the
images below.
Techniques to avoid errors are in bold
Calibration of a mass balance
● Switch the scale on.
● Enter the scale calibration mode, which will be displayed on the screen.
● It will show a flashing weight on the screen; find the appropriate mass shown
on the screen and place it on the scale.
● When the weight on the screen stops flashing, the scale is working properly.
● The balance will usually display the weight of the mass required to calibrate.
Add the appropriate mass onto the pan of the balance, wait for the reading
and the calibration is complete.
2
,Unit 2 Learning Aim A L3 Applied Science Year 12
Calibration of a mass balance is highly important as it ensure accurate
measurements of weight , it helps stop the likelyhood of any systematic
errors happening during titration or the use of the mass balance.
I calibrated the balance as its a important step to make sure measurements are
precise and accurate. The calibration of a balance makes sure the balance
provides the correct weight measurements , particularly in this Na2CO3.
Accurate measurements are important for preparing solutions with precise
concentrations , that affects the outcome results of titration.Calibration helps
to ensure the balance's constant functioning. That consistency is critical for
obtaining repeatable findings in titration studies.Calibrating the balance helps
to reduce systematic mistakes. Mechanical wear, temperature variations, and
electrical drift are all potential causes oLab quality control procedures include
routine calibration. It contributes to ensuring that the titration results are
reliable and satisfy the necessary requirements for precision and accuracy.f
these inaccuracies. Calibration allows the fixing of these problems. Many
laboratories, particularly those following to Good Laboratory Practice (GLP) or
other regulatory requirements, need frequent calibration of their equipment.
The following of these requirements assures that the measurements fulfil
quality and accuracy requirements. Knowing that the balance is correctly
calibrated increases confidence in the accuracy of the titration findings. This
is needed in analytical chemistry, where exact measurements are
required.Regular calibration and maintenance can help extend the life of the
balance.
Calibrate a PH metre:
● First place the electrode in a pH7 solution. After roughly 1 minute the
measurement had enough time to stabilise. The pH meter should indicate a
Ph value of 7. If this is not the case, establish the pH metre at this value.
● Rinse the electrode well with distilled water and then place the electrode in
the pH4 buffer solution
● . If the pH meter is not cleaned out properly with distilled water , leftover
substances can mix with the new pH solution and interfere with the
calibration and measurements , causing inaccuracy.
● Repeat these steps until a reliable measurement is obtained. The pH meter
will then indicate a value by measuring the pH4 solution. The further this value
is from the pH4 value, the greater the inaccuracy of your measuring
instrument.
Calibrating pH probe
● Rinse in water and air dry the pH probe
3
, Unit 2 Learning Aim A L3 Applied Science Year 12
● Dip probe in first buffer solution, stirring until pH readings stay consistent
● Record the pH reading and the known pH of the buffer solution
● Rinse and repeat for at least one more buffer solution
I calibrated the pH probe as finding the exact endpoint is important in
titrations, particularly those containing acids and bases. The pH probe helps in
pinpointing the precise moment when the reaction is finished. The titration
endpoint is correctly identified when the probe's measurements are accurate,
which is ensured via calibration. Calibrating the pH probe aligns its readings
with the known pH standards.The calibration process correscts any
inconsistencies or drifts in the pH probes measurements , making sure that
the readings during titration are as accurate and reliable as possible.The pH
probe constantly provides reliable readings over time with regular calibration.
For titration tests to produce repeatable findings, they require accurate
monitoring of pH changes, this consistency is essential.The pH probe may
provide inaccurate readings if it is not calibrated because of things like
unclean electrodes, ageing electrodes, or variations in the probe's reaction. By
reducing these inaccuracies, calibration raises the titration findings' overall
accuracy.In laboratories, calibration is a crucial component of quality control
procedures. It assists in guaranteeing the accuracy and compliance with
necessary quality requirements of the pH readings made during titration.There
is trust in the titration findings since the pH probe is calibrated correctly. This
is especially significant for analytical chemistry, as accurate and exact pH
measurements are essential for valid data.
How to calibrate a volumetric pipette
This image shows a Volumetric pipette with the pipette filler bulb to draw up
the liquid.
4
Assignment 2A – Calibrations
Introduction:
In this assignment I will be discussing and explaining the calibration of equipment
and how it helped my results with accuracy. I will be explaining the preparation of
Na2CO3 , standardisation of HCl and the method of titration with NaOH and HCl. I
will be finding the concentration and moles of NaOH for both of my titration methods
(indicators and pH metres). I will be explaining how I did the titration using pH
metres and indicators , discussing the difference between the two while comparing
my results with peers. I will be identifying errors that can be made , how to avoid
them and how these errors can affect the accuracy of results. I will also be plotting a
curve for the pH metre titration and using the equivalence point to find the
concentration of NaOH.
Calibration- checking a measuring instrument to check if it is accurate.
Colorimetry- measurement of colour replacing the numeracy system.
Titration is where the solution has a known concentration and determines the
concentration of an unknown acid or alkali solutions using equipment and glassware.
Set up for titration
Firstly, the apparatus should
be set up in the labelled
image.
Reasons of importance for
the accuracy of the
experiment using certain
equipment:
The burette clamp is to make
sure the burette doesn’t move.
The volumetric flasks
measure volumes to a given
mark giving high accuracy as
they are specifically designed
to hold a certain amount of
liquid , this ensures that the volume of liquid during the titration is known precisely
.
1
,Unit 2 Learning Aim A L3 Applied Science Year 12
A Burette is used to measure and distribute amounts of either liquid or gas, the
calibration of a burette reduces the number of systematic errors in titration by
ensuring it gives accurate measurements of the dispensed liquid.
Safety pipette filler is made of rubber and is used to draw liquid into pipettes, this
reduces the risk of pipetting when handling toxic, corrosive or bad-smelling liquids.
pH meter is a piece of equipment used to measure the acidity or alkalinity of a liquid.
They are good for accuracy as human error can't affect the accuracy of their
readings.
pH probe - an instrument used to measure hydrogen ion activity in a solution.
The ph metre has 2 electrodes measuring the solutions' hydrogen ion activity. The
ions exchange a voltage and that is measured by the ph metre.
A test probe is a device used to connect electronic test equipment to a device under
a test.
The need to calibrate pH metres is for accuracy and to make sure your
measurements are reliable.
Other ways to measure pH:
● The indicator method, where an indicator solution turns a certain colour to
know what pH it is.
● A red and blue litmus paper, where if the solution turns blue on the red litmus
paper it means it's an acid, and if the solution turns red on the blue litmus
paper.
● pH paper which turns a specific colour for each pH value, shown in the
images below.
Techniques to avoid errors are in bold
Calibration of a mass balance
● Switch the scale on.
● Enter the scale calibration mode, which will be displayed on the screen.
● It will show a flashing weight on the screen; find the appropriate mass shown
on the screen and place it on the scale.
● When the weight on the screen stops flashing, the scale is working properly.
● The balance will usually display the weight of the mass required to calibrate.
Add the appropriate mass onto the pan of the balance, wait for the reading
and the calibration is complete.
2
,Unit 2 Learning Aim A L3 Applied Science Year 12
Calibration of a mass balance is highly important as it ensure accurate
measurements of weight , it helps stop the likelyhood of any systematic
errors happening during titration or the use of the mass balance.
I calibrated the balance as its a important step to make sure measurements are
precise and accurate. The calibration of a balance makes sure the balance
provides the correct weight measurements , particularly in this Na2CO3.
Accurate measurements are important for preparing solutions with precise
concentrations , that affects the outcome results of titration.Calibration helps
to ensure the balance's constant functioning. That consistency is critical for
obtaining repeatable findings in titration studies.Calibrating the balance helps
to reduce systematic mistakes. Mechanical wear, temperature variations, and
electrical drift are all potential causes oLab quality control procedures include
routine calibration. It contributes to ensuring that the titration results are
reliable and satisfy the necessary requirements for precision and accuracy.f
these inaccuracies. Calibration allows the fixing of these problems. Many
laboratories, particularly those following to Good Laboratory Practice (GLP) or
other regulatory requirements, need frequent calibration of their equipment.
The following of these requirements assures that the measurements fulfil
quality and accuracy requirements. Knowing that the balance is correctly
calibrated increases confidence in the accuracy of the titration findings. This
is needed in analytical chemistry, where exact measurements are
required.Regular calibration and maintenance can help extend the life of the
balance.
Calibrate a PH metre:
● First place the electrode in a pH7 solution. After roughly 1 minute the
measurement had enough time to stabilise. The pH meter should indicate a
Ph value of 7. If this is not the case, establish the pH metre at this value.
● Rinse the electrode well with distilled water and then place the electrode in
the pH4 buffer solution
● . If the pH meter is not cleaned out properly with distilled water , leftover
substances can mix with the new pH solution and interfere with the
calibration and measurements , causing inaccuracy.
● Repeat these steps until a reliable measurement is obtained. The pH meter
will then indicate a value by measuring the pH4 solution. The further this value
is from the pH4 value, the greater the inaccuracy of your measuring
instrument.
Calibrating pH probe
● Rinse in water and air dry the pH probe
3
, Unit 2 Learning Aim A L3 Applied Science Year 12
● Dip probe in first buffer solution, stirring until pH readings stay consistent
● Record the pH reading and the known pH of the buffer solution
● Rinse and repeat for at least one more buffer solution
I calibrated the pH probe as finding the exact endpoint is important in
titrations, particularly those containing acids and bases. The pH probe helps in
pinpointing the precise moment when the reaction is finished. The titration
endpoint is correctly identified when the probe's measurements are accurate,
which is ensured via calibration. Calibrating the pH probe aligns its readings
with the known pH standards.The calibration process correscts any
inconsistencies or drifts in the pH probes measurements , making sure that
the readings during titration are as accurate and reliable as possible.The pH
probe constantly provides reliable readings over time with regular calibration.
For titration tests to produce repeatable findings, they require accurate
monitoring of pH changes, this consistency is essential.The pH probe may
provide inaccurate readings if it is not calibrated because of things like
unclean electrodes, ageing electrodes, or variations in the probe's reaction. By
reducing these inaccuracies, calibration raises the titration findings' overall
accuracy.In laboratories, calibration is a crucial component of quality control
procedures. It assists in guaranteeing the accuracy and compliance with
necessary quality requirements of the pH readings made during titration.There
is trust in the titration findings since the pH probe is calibrated correctly. This
is especially significant for analytical chemistry, as accurate and exact pH
measurements are essential for valid data.
How to calibrate a volumetric pipette
This image shows a Volumetric pipette with the pipette filler bulb to draw up
the liquid.
4
