• Question: Can you say something has dissloved even if you can see its effects. Say if hot chocolate powder 'dissolves' is it really dissolved even though you can still see it in the colour of the liquid?

    Asked by maximillian to Amy, Drew, Julia, Kimberley, Sara on 22 Jun 2011.
    • Photo: Julia Griffen

      Julia Griffen answered on 20 Jun 2011:

      Something is dissolved when you can not longer see the ‘bits’.
      But yes you can say something is dissolved when you can’t see any more ‘bits’ or particles which causes a change of colour.

      Hot chocolate probably isn’t the best of examples…. as its more likely to be a suspension which means the powder of the hot chocolate is mixed really well throughout the whole solution….and milk isn;t possible the best example as milk is actually an emulsion, which means very small blobs /bubbles/ capsules of fat is finely mised in within the water of the milk.

      Another clearer example may jelly. You dissolve jelly (either crystals or cubes) into water. the water changes colour, and still remains transparant (you can see through it)…

      If anyone can think of any better examples… my mind is blank..!

    • Photo: Amy MacQueen

      Amy MacQueen answered on 20 Jun 2011:

      Hey max! yeah i think you can – like those effervescent vitamin C tablets. you stick ’em in water and they fizz away until they are all dissolved. The water turns orange so you can see that there has been an effect but the vitamin C has dissolved! Vitamin C is a water-soluble vitamin! 🙂

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 22 Jun 2011:

      Hi maximillian. Yes you can see when things have dissolved! Dissolution is the process by which solid particles break apart and loose their crystalline structure to become part of a liquid. I think Julia may be right about the hot chocolate example. But Amy’s provided another great example of watching dissolution in progress! I love those vitamin C packets – they are fun to watch!!