• Question: What sort of chemicals do you use when doing a chemical test?

    Asked by january to Andrew, Daniel, Hayley, Natalia, Peta on 25 Nov 2011.
    • Photo: Andrew Cairns

      Andrew Cairns answered on 18 Nov 2011:

      We use several main groups of chemicals in our experiments:

      1) Transition Metal Nitrates. Transition metals are a large section of the periodic table where most of the coloured metals are, for example, gold, silver, cobalt, iron. We use nitrates because they dissolve.

      2) Metal cyanides – very very dangerous!

      We do different things with them e.g. heating up mixtures, mix them slowly etc to get different results.

    • Photo: Hayley Smith

      Hayley Smith answered on 18 Nov 2011:

      When doing a chemical test you want to use chemicals that are going to react to give a certain outcome, and an outcome that is easy to measure or easily observed – this could be a colour change, or release of a certain amount fo gas etc. I’ve not really done any chemical tests since I left school (since I’ve been more physics-y based) but at school I do remember doing titration experiments in chemistry where there were noticeable colour changes, we used a chemical called Phenolphthalein (I think) that went from clear to pink. I also remember using other acids and doing litmus paper tests and also using iodine when doing chemical tests for starch in biology.

    • Photo: Daniel Scully

      Daniel Scully answered on 18 Nov 2011:

      Particle physicists don’t need to do chemical tests very often.

      One of the most famous particle experiments though used a giant tank of cleaning fluid to look for particles (neutrinos) coming from the Sun. When that particle stopped in the tank it would change one of the atoms in the tank to a different element.

      The guy doing the experiment then managed, using some chemical magic as far as I can tell, to count how many atoms were changed, thus counting the number of particles coming from the Sun. Which I think is pretty impressive.

    • Photo: Peta Foster

      Peta Foster answered on 25 Nov 2011:

      I don’t actually do chemical tests… at the intensities my laser reaches there are no atoms left let alone molecules and you need molecules for chemistry 😀

      I do use chemicals for things though. I use ethanol which is a alcohol with each molecule having 2 carbon atoms in it. We use the ethanol for cleaning our optics. We need to clean them in they get any bits on them because those bits will scatter and diffract the laser and make hot spots in the beam… those hot spots can then burn our other optics. 🙁 so we clean the mirrors and then we only blow up the target which we intended to blow up 😀

      I loved chemistry at a’level though and hope you are enjoying it too 😀