Name: malik Ahmed
Unit 2: practical scientific procedures and techniques
Learning aim, A: undertake titration to determine the
concentration of solutions.
Aim of assessment
This assessment required me to find the concentration of
an unknown sample of sodium hydroxide (NaOH).
To do this, I first had to find the concentration of the
hydrochloric acid (HCl) I was going to use by titrating the
HCl against a standard solution of sodium carbonate
(Na2CO3).
Calibration of balance
Measuring a weighting boat to calibrate the balance
Try 1 Try2 Try3
1.07 1.07 1.07
Method: P1, P2,M1
Using a mass of 10 g, I calibrated the balance. First of all, the power
was plugged into the balance and the balance zeroed. Secondly, I put
on the balance a mass of 10 g and then reported my findings. Then I
put another 10 g mass on the equilibrium to record the 20 g weight.
Finally, to record the weight, I put another 10 g of mass for 30 g and
another 10 for 40 g and a further 10 for 50 g. I then repeated this 3
times so that I could compare my observations to see if my results
were close to the benchmark.
Equipment used:
Balance
10g masses
Calibration of the masses
Known Measured
mass (g) masses on
balance (g)
1
, 1st 2nd 3rd Mean
10 10.07 10.07 10.07 10.07
20 20.04 20.03 20.03 20.0333
30 30.10 30.09 30.09 30.0333
40 40.24 40.24 40.24 40.24
50 50.32 50.32 50.32 50.32
Problems and issues that occurred
The 10g masses were not as precise as they are supposed to be an
exact 10g but have extra weight of 0.7 or more. I would get different
weight and measure them before I use them so that my results are
accurate
Accuracy, precision and reliability
1. Accuracy: my observations were close to the benchmark. This is
because my observations did not reach 1 gram over 10 g.
2. Precision: as the measurements were close together, my findings
were accurate. For e.g., I got 10.07 0n for my first set of results for
all three tries.
3. Reliability: since my findings were very similar to each other, my
results were accurate.
Hazards and risks
While performing the calibration, I did not face any risk. The key risks
were that the masses were able to fall and damage the lower body.
However, the chances of it dropping are poor if the masses are put in the
middle of the table.
Improvement D1
By making my weights to the exact measurements I need, I could enhance
my calibration. This will prohibit me from having any additional decimal
points.
Calibration of the volumetric pipette
Equipment:
Pipette
Beaker
Distilled water
2
Unit 2: practical scientific procedures and techniques
Learning aim, A: undertake titration to determine the
concentration of solutions.
Aim of assessment
This assessment required me to find the concentration of
an unknown sample of sodium hydroxide (NaOH).
To do this, I first had to find the concentration of the
hydrochloric acid (HCl) I was going to use by titrating the
HCl against a standard solution of sodium carbonate
(Na2CO3).
Calibration of balance
Measuring a weighting boat to calibrate the balance
Try 1 Try2 Try3
1.07 1.07 1.07
Method: P1, P2,M1
Using a mass of 10 g, I calibrated the balance. First of all, the power
was plugged into the balance and the balance zeroed. Secondly, I put
on the balance a mass of 10 g and then reported my findings. Then I
put another 10 g mass on the equilibrium to record the 20 g weight.
Finally, to record the weight, I put another 10 g of mass for 30 g and
another 10 for 40 g and a further 10 for 50 g. I then repeated this 3
times so that I could compare my observations to see if my results
were close to the benchmark.
Equipment used:
Balance
10g masses
Calibration of the masses
Known Measured
mass (g) masses on
balance (g)
1
, 1st 2nd 3rd Mean
10 10.07 10.07 10.07 10.07
20 20.04 20.03 20.03 20.0333
30 30.10 30.09 30.09 30.0333
40 40.24 40.24 40.24 40.24
50 50.32 50.32 50.32 50.32
Problems and issues that occurred
The 10g masses were not as precise as they are supposed to be an
exact 10g but have extra weight of 0.7 or more. I would get different
weight and measure them before I use them so that my results are
accurate
Accuracy, precision and reliability
1. Accuracy: my observations were close to the benchmark. This is
because my observations did not reach 1 gram over 10 g.
2. Precision: as the measurements were close together, my findings
were accurate. For e.g., I got 10.07 0n for my first set of results for
all three tries.
3. Reliability: since my findings were very similar to each other, my
results were accurate.
Hazards and risks
While performing the calibration, I did not face any risk. The key risks
were that the masses were able to fall and damage the lower body.
However, the chances of it dropping are poor if the masses are put in the
middle of the table.
Improvement D1
By making my weights to the exact measurements I need, I could enhance
my calibration. This will prohibit me from having any additional decimal
points.
Calibration of the volumetric pipette
Equipment:
Pipette
Beaker
Distilled water
2
