Unit 2 Assignment A- Titration and Colorimetry
I was given the task to determine the concentration of a solution using different scientific
procedures and techniques. I had to use an indicator and a pH meter to perform a titration to
determine the concentration of a solution of sodium hydroxide and colorimeter to figure out
the concentration of 2 different copper (II) sulphate samples.
Calibration-
Before I started my experiments, I first calibrated my equipment to ensure accuracy and
precision. The equipment I had to calibrate include: a weighing balance, pipette, burette, PH
meter and a volumetric flask. Whilst calibrating equipment, it is advisable to keep all the
equipment in the same room long enough so that they are all at the same temperature as
temperature can affect the reading of equipment and therefore can alter results and reduce
precision and accuracy. Calibration is a necessary part of all experiments as it ensures
accuracy and precision as if the equipment being used isn't exact then it can alter and
change results.
Weighing balance-
When calibrating a weighing balance, certified weights are used. Certified weights are
weights with a specific weight. I placed these on my weighing balance and recorded the
readings. Overall, I had determined my weighing scales to be in an adequate rage of
accuracy. If they were not accurate enough then they could be adapted and changed
accordingly.
Certified Reading 1 Reading 2 Reading 3 Reading 4 Mean mass
mass
200g 199.96 199.95 199.94 199.95 199.95
30g 29.99 30.00 30.00 29.99 29.995
50g 49.97 49.98 49.97 49.94 49.973
3g 3.00 3.00 3.00 3.00 3.00
I was able to work out the mean mass using the equation: volume= mass/density
As the error of my weighing balance was very low, I decided that no adjustments were
needed so I decided to use them to perform my experiment.
Burette-
To calibrate a burette, I first rinsed it with distilled water to ensure it was clean. Then I took a
clean beaker and weighed it and recorded its mass. I then filled up my burette with water
and rinsed some out so that the tap was filled, and the meniscus was on 0 at eye level. I
placed my empty beaker under my burette and proceeded to release exactly 10cm3 of water
into it and then weighed my beaker. I repeated this until I had released 10cm3, 20cm3 and
50cm3 of water. Overall, I determined my burette to be in a good range of accuracy and
therefore fit for use.
Indicated volume (ml) Mass of water dispensed (g) Calculated volume (ml)
10 10.00 10.00
20 20.19 20.15
50 50.10 50.24
Pipette-
, When calibrating my 25cm3 pipette, I first weighed a beaker and recorded its weight. Next, I
filled up the pipette with distilled water up to its specific graduation mark, making sure to look
at the meniscus at eye level, and allowed the water to pour into the empty beaker. I waited a
few seconds to allow every drop of water to come out and tapped the tip of my pipette onto
the side of the beaker, and then I weighed the beaker and worked out how accurate the
instrument was. Overall, I did not deem my pipette to be accurate enough to use as its
uncertainty should be +/- 0.06cm3 but my results were well out of this range, so I decided to
get another pipette so that I could have more accurate results.
Trial 1 Trial 2 Trial3
Mass of water (g) 24.78 24.82 24.75
Volume of water (cm3) 24.85 24.89 24.82
Volumetric flask-
I calibrated my volumetric flask by first weighing and recording its mass when empty. I then
filled it up to its graduation mark with water, ensuring to use a dropping pipette when I was
about 1 inch underneath the graduation mark to ensure complete accuracy and precision.
Then, once the bottom of my meniscus was on the graduation mark at eye level, I reweighed
the beaker and worked out its accuracy.
I decided that my flask had a very low error and was within the tolerance, so I decided to use
it for my experiment.
Flask 1 2 3
Mass of beaker filled 343.81 343.84 343.84
with water (g)
Mass of empty beaker 95.80 95.80 95.80
(g)
Mass of water (g) 248.73 248.04 248.04
Volume of water (ml) 248.73 248.76 248.76
pH meter-
The next item that was calibrated was my pH meter. This was done by placing the meter
into two different certified solutions (pH7 and pH4) and allowing the readings to settle. If the
readings were not accurate, I took a screwdriver and adjusted the readings until they were
correct. In the end I was left with a perfectly calibrated pH meter.
Making a standard solution of sodium carbonate-
To find out the concentration of my sodium hydroxide solution, I had to react it with
hydrochloric acid. However, the concentration of my hydrochloric acid was unknown and
therefore I had to figure out its concentration. This was easily done by reacting my HCl with
a standard solution of sodium carbonate. A standard solution is a solution of a known
concentration. To accurately compose my standard solution of sodium carbonate, I had to
first calibrate my weighing balance using certified weights and adjusting the weights where
necessary. Then, I accurately weighed out 1.5g of anhydrous sodium carbonate in a
weighing boat and carefully transferred it all into a beaker. I rinsed the weighing boat with
distilled water and poured it into the beaker to make sure none of it was left behind and then
I accurately worked out the exact mass of sodium carbonate that was transferred. I
continued to fill up the beaker with distilled water until there was about 150cm3 of water in it
and then I stirred the solution until my solid was completely dissolved. Next, using a funnel,
I transferred my solution from the beaker into a volumetric flask and filled the 250cm3 flask
up with distilled water until the meniscus was on the line. I made sure to rinse the funnel,
glass
I was given the task to determine the concentration of a solution using different scientific
procedures and techniques. I had to use an indicator and a pH meter to perform a titration to
determine the concentration of a solution of sodium hydroxide and colorimeter to figure out
the concentration of 2 different copper (II) sulphate samples.
Calibration-
Before I started my experiments, I first calibrated my equipment to ensure accuracy and
precision. The equipment I had to calibrate include: a weighing balance, pipette, burette, PH
meter and a volumetric flask. Whilst calibrating equipment, it is advisable to keep all the
equipment in the same room long enough so that they are all at the same temperature as
temperature can affect the reading of equipment and therefore can alter results and reduce
precision and accuracy. Calibration is a necessary part of all experiments as it ensures
accuracy and precision as if the equipment being used isn't exact then it can alter and
change results.
Weighing balance-
When calibrating a weighing balance, certified weights are used. Certified weights are
weights with a specific weight. I placed these on my weighing balance and recorded the
readings. Overall, I had determined my weighing scales to be in an adequate rage of
accuracy. If they were not accurate enough then they could be adapted and changed
accordingly.
Certified Reading 1 Reading 2 Reading 3 Reading 4 Mean mass
mass
200g 199.96 199.95 199.94 199.95 199.95
30g 29.99 30.00 30.00 29.99 29.995
50g 49.97 49.98 49.97 49.94 49.973
3g 3.00 3.00 3.00 3.00 3.00
I was able to work out the mean mass using the equation: volume= mass/density
As the error of my weighing balance was very low, I decided that no adjustments were
needed so I decided to use them to perform my experiment.
Burette-
To calibrate a burette, I first rinsed it with distilled water to ensure it was clean. Then I took a
clean beaker and weighed it and recorded its mass. I then filled up my burette with water
and rinsed some out so that the tap was filled, and the meniscus was on 0 at eye level. I
placed my empty beaker under my burette and proceeded to release exactly 10cm3 of water
into it and then weighed my beaker. I repeated this until I had released 10cm3, 20cm3 and
50cm3 of water. Overall, I determined my burette to be in a good range of accuracy and
therefore fit for use.
Indicated volume (ml) Mass of water dispensed (g) Calculated volume (ml)
10 10.00 10.00
20 20.19 20.15
50 50.10 50.24
Pipette-
, When calibrating my 25cm3 pipette, I first weighed a beaker and recorded its weight. Next, I
filled up the pipette with distilled water up to its specific graduation mark, making sure to look
at the meniscus at eye level, and allowed the water to pour into the empty beaker. I waited a
few seconds to allow every drop of water to come out and tapped the tip of my pipette onto
the side of the beaker, and then I weighed the beaker and worked out how accurate the
instrument was. Overall, I did not deem my pipette to be accurate enough to use as its
uncertainty should be +/- 0.06cm3 but my results were well out of this range, so I decided to
get another pipette so that I could have more accurate results.
Trial 1 Trial 2 Trial3
Mass of water (g) 24.78 24.82 24.75
Volume of water (cm3) 24.85 24.89 24.82
Volumetric flask-
I calibrated my volumetric flask by first weighing and recording its mass when empty. I then
filled it up to its graduation mark with water, ensuring to use a dropping pipette when I was
about 1 inch underneath the graduation mark to ensure complete accuracy and precision.
Then, once the bottom of my meniscus was on the graduation mark at eye level, I reweighed
the beaker and worked out its accuracy.
I decided that my flask had a very low error and was within the tolerance, so I decided to use
it for my experiment.
Flask 1 2 3
Mass of beaker filled 343.81 343.84 343.84
with water (g)
Mass of empty beaker 95.80 95.80 95.80
(g)
Mass of water (g) 248.73 248.04 248.04
Volume of water (ml) 248.73 248.76 248.76
pH meter-
The next item that was calibrated was my pH meter. This was done by placing the meter
into two different certified solutions (pH7 and pH4) and allowing the readings to settle. If the
readings were not accurate, I took a screwdriver and adjusted the readings until they were
correct. In the end I was left with a perfectly calibrated pH meter.
Making a standard solution of sodium carbonate-
To find out the concentration of my sodium hydroxide solution, I had to react it with
hydrochloric acid. However, the concentration of my hydrochloric acid was unknown and
therefore I had to figure out its concentration. This was easily done by reacting my HCl with
a standard solution of sodium carbonate. A standard solution is a solution of a known
concentration. To accurately compose my standard solution of sodium carbonate, I had to
first calibrate my weighing balance using certified weights and adjusting the weights where
necessary. Then, I accurately weighed out 1.5g of anhydrous sodium carbonate in a
weighing boat and carefully transferred it all into a beaker. I rinsed the weighing boat with
distilled water and poured it into the beaker to make sure none of it was left behind and then
I accurately worked out the exact mass of sodium carbonate that was transferred. I
continued to fill up the beaker with distilled water until there was about 150cm3 of water in it
and then I stirred the solution until my solid was completely dissolved. Next, using a funnel,
I transferred my solution from the beaker into a volumetric flask and filled the 250cm3 flask
up with distilled water until the meniscus was on the line. I made sure to rinse the funnel,
glass
