MediumChemistryHigh School (9–10)GeneralMixtures and Solutions › Mixtures, Solutions and ColloidsConceptualBoard Exam
A liquid looks like one clear, uniform substance…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A liquid looks like one clear, uniform substance. A beam of light from a torch passes through it, and the path of the beam can be seen.
- Is the liquid a true solution? Explain.
- What kind of mixture could it be?
- Describe one more test that shows it is not a suspension.
Need a reminder? The key ideaShow
Solution: particles under , invisible, never settle, pass through filters, do not scatter light. Colloid: to , never settle, cannot be filtered, scatter light (the Tyndall effect). Suspension: large particles that can be seen, settle and can be filtered.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) No. The particles of a true solution are too small to scatter light, so a beam through it cannot be seen.
Step 2. (b) A colloid. Its particles are big enough to scatter light (the Tyndall effect), but too small to be seen.
Step 3. (c) Leave it to stand for a day: a colloid does not settle, but a suspension does. Or pour it through filter paper: nothing stays behind from a colloid.
Answer: It is not a true solution; it is a colloid, and standing or filtering shows it is not a suspension.
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