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31/01/2020 at 11:28am

How does a lava lamp work?

Why don't the oil and water mix?

lava lamp

Comments that people have made about this blog post

Comment 1 Comment by Sam B on 17 Oct 14 at 8:12pm | Quote this comment
In a liquid motion lamp, the heat usually comes from a light bulb. The heavier liquid absorbs the heat, and as it heats up, it expands. As it expands it becomes less dense. Because the liquids have very similar densities, the formerly heavier liquid is suddenly lighter than the other liquid, so it rises.
Every noticed that if you apply oil on your hand and wash it under water, the water doesn't stick to your hand? Or how when a drop of oil falls in a glass of water, it floats on the surface instead of mixing? Well, this is called Hydro phobic.
Comment 2 Comment by Lauren C on 18 Oct 14 at 1:03pm | Quote this comment
Water molecules are polar – they have a small positive charge at one end and a small negative charge at the other end, and they stick to each other. Oil molecules are non-polar – they have no charge. Because of this, oil molecules are more attracted to each other than to water molecules, and water molecules are more attracted to each other than to oil molecules.

Oil and water can be forced to mix together by adding an emulsifier (see 'Making an Emulsion'). This creates a stable mixture of water with droplets of oil spread through it, or oil with droplets of water spread through it, that does not settle out.
Comment 3 Comment by Mr Ryan on 18 Oct 14 at 3:07pm | Quote this comment
Guys, be careful of plagiarism. This is when you have copied and pasted someone else's work without crediting where you got the text from and pass it off as your own work. Perhaps Mrs Lamb could talk more about this issue within your e-safety sessions in class.
Comment 4 Comment by Connie M on 20 Oct 14 at 1:06pm | Quote this comment
It all starts when you add 375ml of veggie oil to a plastic bottle now add 125ml of water and 10 drops of food coulring when you add a torch under neath th bottle it all lights up. Know you can add a alka seltza tablets and you will have a lave lamp.Bubbles will start appering this is carbon dioxide forming bubbles around food coulring the oil will be at the top [hidrophobic] and the water and food coulering will be at the bottom [hidrophillic]
Comment 5 Comment by Zoe B on 20 Oct 14 at 1:08pm | Quote this comment
The oil is hydrophobic liquid,that means it doesn't like water.The hydrophillic is the water and the food colouring that means they both love water.The carbon dioxide is the Alka-Seltza which makes it bubble.The 10 drops of food colouring floats straight to the bottom because it loves the water while the 375ml of oil doesn't like the water so that it stays at the top add the water so that the bottle is filled,now break the tablets into quarters and quickly put them in and put the lid on.Now just watch it bubble! :lol:
Comment 6 Comment by Florence T on 20 Oct 14 at 1:09pm | Quote this comment
Water doesnt mix with oil because oil is hydrophobic and water is hydrophillic :-)
Comment 7 Comment by Jamie B on 20 Oct 14 at 1:15pm | Quote this comment
A lava lamp has 4 key ingrediants: oil (hydrophobic), water and food colouring (hydrophillic), alka seltza tablet(carbon dioxide) and bubbles. Once you have added the oil and the water weirdly the water will drop down to the bottom because oil dosen't like water and it wants to escape.

When you put your 10 drops of food colouring in your mixture the water will turn red. After you have dropped your alka seltza tablet in it will turn into red bubbles because it has collected the food colouring. The bubbles go up and down at different times.
Comment 8 Comment by Dylan L on 20 Oct 14 at 1:16pm | Quote this comment
Oil (the hydrophobic) doesn't like water, so when you add water and food dye it drops to the bottom of the bottle with water because food dye is hydrophillic so it loves water!. Add the alka seltza and the carbon dioxide takes food up with it in coloured bubbles which ascends and descends.
Comment 9 Comment by Andy S on 20 Oct 14 at 1:16pm | Quote this comment
8) Water and vegetable oil don't mix together because oil is hydrophobic and water doesn't mix well with it. the food colouring mixes well because it is hydrophillic. That is why it stays at the bottom (because it likes mixing with water). The bubbles are red because they collect the red food colouring . If you watch the lava lamp you will realiise that the bubbles never go all up at the same time. same with when they are going down.

By Andy.S
Comment 10 Comment by Mary L on 20 Oct 14 at 1:19pm | Quote this comment
Our lava lamps make bubbles by using selza tablets,food dye,oil and water. the oil is a hydophobic and the water is a hydrophillic therefore the oil floats to the top and the water sinks. when we added the food dye it meant that the bubbies turned red and floated upwards

By MillieT and MaryL
Comment 11 Comment by Kira N on 20 Oct 14 at 1:19pm | Quote this comment
A lava lamp works when the oil, alk zeltza tablets, water and food coluoring mixes together to create bubbles that when a torch is shone underneeth it the heat cuases the bubbles to asende then when it bets colder it desendes to the bottom again. The oil is hydrophobic and it does not mix with water that is hydrophillic so when oil is spilled it will not comme off.

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