Essay
Learning aim, A: Undertake titration to determine the concentration of a solution.
- Course
- Institution
Grade D* achieved great and easy source that can be used as a reference point.
[Show more]
Seller
Follow
asma2
Content preview
Unit 2: Practical Scientific Procedures and Techniques.Learning aim, A: Undertake titration to determine the concentration of a solution.
Aim of the assessment- The aim of this assessment is to find the exact concentration of an unknown
sample of sodium hydroxide (NaOH). To do this find the concentration of hydrochloric acid that you are
going to be titrating the HCl against a standard solution of sodium carbonate.
Calibrating a balance-
Equipment needed.
1. Balance
2. Masses- 10g, 20g, 30g, 40g and 50g
Method P1, P2,M1
1. Turn on the balance and leave the device for a satisfactory amount of time to allow it to reach a
thermal equilibrium (approximately a minute).
2. Add a known mass of 10g to the balance.
3. Record the mass and repeat this step three times.
4. When you record each of the values calculate the average. This can be done by adding the values of
each mass together and then dividing them by the number of values there are (excluding the
anomalies).
5. For example, 10.07 + 10.07 + 10.07 = 30.21, 32.1/ 3 = 10.07.
6. Repeat steps 2-5 using masses of 20g, 30g, 40g and 50g.
7. Record the results in a table like the one below.
Calibrating a balance result
Known Measured masses on a balance(g)
, masses. 1st (g) 2nd (g) 3rd (g) Average(g) (2d.
(g) p)
10 10.07 10.07 10.07 10.07
20 20.04 20.03 20.03 20.03
30 30.10 30.09 30.09 30.13
40 40.24 40.24 40.24 40.24
50 50.32 50.32 50.32 50.32
Average of the masses
The average of these masses shows that the balance has been calibrated correctly as the values are close
together. This shows that they are accurate increasing the reliability of the results when the material is
weighed out.
Problems that occurred during the experiment
There were some limitations when weighing the 20 and the 30 kg masses. The 20 kg mass weighed 20.04
then 20.03and then 20.03. Then the 30 kg mass weighed had the same problem. The first measurement
weighed 0.01 more than the second two. However, this is down to human error and there for cannot be
avoided.
Accuracy, precision, and reliability
Accuracy- The results were close to benchmark. This is because the results were not more or less than 0.01
away from the exact value.
Precision- The results were precise as the repeat measurements were either the same or very near each
other. For example, 20.04 and 20.03 are 0.01 away from each other.
Reliability- The results were reliable as close together.
, Hazards, risks, and prevention
There were no hazards in this experiment. However, the masses could have fallen and caused damage to
the lower half of the body. This can be prevented by placing the balance on the middle of the table.
Improving the experiment D1
The experiment could be improved by using a balance that can weigh more decimal places. This would
prevent any errors from occurring.
Calibration of a volumetric pipette
The maximum for the volumetric pipette is 25cm3.
Equipment needed.
1. Beaker (50ml)
2. Pipette (25cm3)
3. Distilled water
4. Balance
P1, P2, M1
Method
1. Place a clean dry beaker on the balance and then proceed to zero the balance to eliminate the mass
of the beaker.
2. Suck up distilled water into the pipette so that the bottom of the meniscus sets on the 25cm 3 line.
3. Carefully dry the tip of the volumetric pipette with a paper towel to make sure no drips enter the
beaker. Ensure that you do this step carefully as the tip of the volumetric pipette is fragile.
4. Transfer your distilled water into the beaker from the pipette and then proceed to weigh.
5. Place your beaker on a ‘zeroed’ balance and record the mass. Mine was 44.07g.
6. By using the mass from the distilled water, we can find the volume.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller asma2. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.19. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
64438 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now