We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

To Calculate the Percentage Composition of the Mixture of Na2CO3 + NaHCO3

The whole doc is available only for registered users
  • Pages: 3
  • Word count: 691
  • Category: Chemistry

A limited time offer! Get a custom sample essay written according to your requirements urgent 3h delivery guaranteed

Order Now

Aim – To calculate the percentage composition of the mixture of

Na2CO3 + NaHCO3


1) Weigh a perfectly dry crucible with properly fitted lid.

2) Weigh the crucible with 1 gram of the mixture.

3) Heat the crucible with a partially open lid for 10 minutes with low flame and gradually increase the flame.

4) Keep heating for 30 minutes.

5) Place the crucible to a dessicator.

6) Weigh the cooled crucible and note it down.

Equipment used –

1) Crucible

2) Weighing machine

3) Dessicator

4) Bunsen burner

5) Tripod stand

6) Lighter

7) The mixture

Qualitative analysis –

1) The cooling process was time consuming.

2) When the heating started, there were some fumes evolved.

3) In the middle of the process of heating some orange colour deposits could be seen in the tripod stand.

4) It was hard to keep the lid of the crucible partially open, as it was not balancing perfectly.

5) The crucible turned very hot, thus it was hard to place the crucible in the dessicator.

6) The vaseline wasn’t very sticky, thus the lid of the dessicator wasn’t very tight.

7) Once the crucible was placed inside the dessicator, it was difficult to keep the lid partially open as it was too hot to touch and one had to use holder.



Mass of the crucible + 0.001g

Mass of the crucible + mixture + 0.001g

Mass of the mixture + 0.002g

After Heating, Mass of the crucible + 0.001g

Mass lost after heating + 0.002g














2NaHCO3 —- Na2CO3 + CO2 + H2O

Molar mass of 2NaHCO3 = 168

Molar mass of CO2 + H2O = 44 + 18 = 62

As we know the mass of –

CO2 + H2O = 0.222 + 0.002g in the first attempt.

This was calculated by

Mass lost after heating = (Mass of crucible + mixture) – (After heating mass)

This mass loss is the mass of H2O + CO2 which evaporates during the heating process.

Now, to calculate the mass of NaHCO3 can simply be calculated by unitary method as follows –

Let the mass of NaHCO3 be X

168 62

X 0.222

Therefore X = 0.602 + 0.001 g

As we know that the mass of the mixture before heating was 0.837 + 0.002g

The percentage composition of NaHCO3 can be calculated as follows –

(0.602/0.837)*100 = 71.9 %

Therefore, the percentage composition of Na2CO3 is 100 – 71.9 = 28.1 %

Error propagation

The absolute uncertainty of the masses was + 0.002g,

Therefore the percentage uncertainties of the masses were calculated as follows –

(0.002/0.602) * 100 = 0.2 % (rounded of to one significant figure)

(0.002/0.837) * 100 = 0.2 % (rounded of to one significant figure)

Therefore, the uncertainty for the final value of NaHCO3 71.9 + 0.4%

And Na2CO3 = 28.1 + 0.4%

Because the percentage uncertainties are added.

The final answer for the second attempt was =

NaHCO3 = 67.6 + 0.3 %

Na2CO3 = 32.4 + 0.3%

Conclusion –

My final result would be 30.25 + 0.6 % as it is the average of both the attempts made.

The real value of the composition is 30 %

It is quite close and can be concluded that the answer is not exact due to some human errors or impure mixtures.

Evaluation –

1) The answer could have been more accurate and precise if I would have repeated the experiment once more.

2) Could have used better equipment with more precise readings

3) Made sure that the mixture used was pure.

Related Topics

We can write a custom essay

According to Your Specific Requirements

Order an essay
Materials Daily
100,000+ Subjects
2000+ Topics
Free Plagiarism
All Materials
are Cataloged Well

Sorry, but copying text is forbidden on this website. If you need this or any other sample, we can send it to you via email.

By clicking "SEND", you agree to our terms of service and privacy policy. We'll occasionally send you account related and promo emails.
Sorry, but only registered users have full access

How about getting this access

Your Answer Is Very Helpful For Us
Thank You A Lot!


Emma Taylor


Hi there!
Would you like to get such a paper?
How about getting a customized one?

Can't find What you were Looking for?

Get access to our huge, continuously updated knowledge base

The next update will be in:
14 : 59 : 59