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 P5 Science 2011 SA2 Aitong Paper Section B Q31 - Urgent
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By: geniuskids (offline)  Saturday, October 20 2012 @ 12:14 AM CDT (Read 798 times)  
geniuskids

Hi there, I can't find any attachment for the diagram, so you may have to use yr imagination for the diagram.

Q31 : 250ml of blue coloured water was mixed with 250ml of red coloured water. 10g of common salt was then dissolved into the mixture. The mixture was then heated.
Droplets of liquid X were formed on teh sides of the funnel during heating.
(a) How was this liquid X formed?
(I do know this answer)

(b) What is the colour and taste of the liquid X?
(I am puzzled by this question) . Answers from the answer sheet is : Liquid X will be colourless and tasteless.
Can someone pls tell me why is it colourless and tasteless?

Tks

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By: mhbar1986 (offline)  Sunday, October 21 2012 @ 01:42 AM CDT  
mhbar1986

Hi. This question is about evaporation of water.

a) The heated water would evaporate to form hot water vapour. The hot water vapour rises and comes into contact with the cool surface of the funnel and condenses to form water droplets.

b) Only water in the mixture would evaporate. The food colouring and salt would remain behind. Liquid X is pure water formed from the condensation of the water vapour produced during heating.

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By: geniuskids (offline)  Sunday, October 21 2012 @ 03:06 AM CDT  
geniuskids

Thank you for your clear explanation.

So does that mean that when they ask " What is the colour and taste of Liquid X"?
The answer is " Liquid X is Colourless and tasteless since it is pure water". ??

Thank you once again!

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