Elements, compounds and mixtures
Greetings, everyone! Sorry for the long wait, but I'm finally back with a brand-new entry in the blog...Practical 11!
During the course of this practical, we had to conduct an experiment to determine the properties of mixtures and compounds respectively. Here's the list of equipment and resources we would be utilising for carrying out this experiment:
Apparatus
- Tripod stand
- Evaporating dish
- Glass rod
- Wire gauze
- Bunsen burner
Materials
- Sulfur powder
- Iron fillings
- Filter paper
- Piece of paper magnet
We were given some points to take into consideration, namely:
- Both sulfur and iron are elements (i.e. they cannot be broken down into simpler substances through chemical means)
- When mixed, a mixture (surprise, surprise) of iron and sulfur is formed
- When heated together, a compound (iron sulfide) is formed
By recording our observations on the properties of iron, sulfur and iron sulfide, we are able to compare and contrast mixtures and compounds, and thus investigate their similarities and differences. Now, time for the experiment! We had to follow the steps below:
Part 1:
Observing elements
Part 1:
Observing elements
- Place sulfur powder on a piece of filter paper and observe its appearance. Answer: Basically it was yellow in colour (and of course it was a powder -.-)
- Wrap an end of a magnet with a small piece of paper. Bring the magnet into close proximity with the yellow powder and observe what happens. Answer: Nothing happened (sulfur is not magnetic)
- Place iron filings in an evaporating dish and observe its appearance. Answer: Appeared to be a black powder.
- Move magnet close to iron filings and observe what happens. Answer: Iron filings are attracted to the magnet (Iron is a magnetic substance)
Part 2:
Observing a mixture
- Pour the sulfur powder into the dish of iron filings and observe its appearance. Answer: It appeared to be a mixture of black and yellow powder (I know, unbelievable, isn't it?)
- Move the magnet close to the mixture and observe what occurs. Answer: Only the iron filings (a.k.a. the black powder) was attracted to the magnet
Part 3:
Observing a compound
- Heat the evaporating dish (with the mixture of yellow and black powder in it) over a Bunsen burner until no further change is observed. Then, allow some time for the newly-formed compound to cool and observe its appearance. Answer: The compound formed was a dark grey solid.
- Move the magnet close to the compound and observe what happens. Answer: Nothing happens.
Conclusion
So, what can we infer from this experiment?
Firstly, we observed that the mixture retained the same characteristics as its constituent components (that is, the iron filings were still attracted to the magnet).
Secondly, we observed that the compound had different characteristics as compared to its constituent components (despite the fact that iron filings were part of the compound, the compound was not attracted to a magnet).
What, then, caused these differences? The answer lies in how they were formed. The formation of compounds involves heat energy, whereas the formation of mixtures simply involves, well, mixing! This also affects how they are separated. Mixtures can be separated by physical means such as evaporation or distillation, whereas compounds can only be separated via chemical methods.
The things I learnt from this practical are condensed into the following bullet points:
- A mixture can be separated by physical means
- A mixture retains the characteristics of its constituent components
- A compound can only be separated by chemical means
- A compound does not retain the characteristics of its constituent components
That concludes my reflection on Practical 11. Next reflection coming soon!
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Roundup on elements, compounds and mixtures
Hello there! It's been quite a while now since I posted. The deadline for the submission is looming, and thus I will attempt to summarise the remaining practicals into several groups. While this means I will not be covering every practical in great detail, I do hope that this will not affect the quality of my works too much. I hope that from these summaries, one can obtain key information more easily.
Practicals 11 and 12 covered elements, compounds and mixtures. Here is some key information about them:
Elements
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Roundup on elements, compounds and mixtures
Hello there! It's been quite a while now since I posted. The deadline for the submission is looming, and thus I will attempt to summarise the remaining practicals into several groups. While this means I will not be covering every practical in great detail, I do hope that this will not affect the quality of my works too much. I hope that from these summaries, one can obtain key information more easily.
Practicals 11 and 12 covered elements, compounds and mixtures. Here is some key information about them:
Elements
- Consists of only one kind of atom
- Cannot be broken into a simpler substance by either physical or chemical means
- Exist as either atoms or molecules (which are fundamentally 2 or more atoms of the same elements chemically combined)
Compounds
- Formed by chemically combining two or more different elements
- Can be broken down into simpler substances, not through physical means but rather chemical means
- Possess different properties as compared to their constituent components
- The ratio of its constituent components are always the same
Mixtures
- Comprise two or more different elements physically joined together
- Can be separated into its constituent components via physical means
- Retains the properties of its constituent components
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Summary on solutions and suspensions
This topic proved to be quite confusing for me, as I kept getting terms mixed up. I shall attempt to simplify the definitions in the following points:
- A solute is the substance that dissolves to form a solution
- A solvent is the substance in which the solute dissolves
- A solution is a mixture of one or more solutes dissolved in a solvent
- A suspension is a mixture which is not fully dissolved and has insoluble particles dispersed throughout itself
Let us now compare the differences between a solution and a suspension.
Solution | Suspension | |
Appearance | Homogenuous (appearance is same in every part of solution) | Heterogenuous (appearance different in every part of the solution) |
Transparency | Solute particles too small to reflect or block any light passing through the solution (Clear/Transparent) | Insoluble particles large enough to block and prevent light from passing through (Cloudy) |
Filtration | No residue is left behind when a solution is filtered | Insoluble particles in a suspension are left behind when a suspension is filtered |
This concludes the summary on solutions and suspensions. I hope you have found it informative :)
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