Making a solution sheet

Discussion in 'Top Tips' started by Techitude, Oct 9, 2019.

  1. Techitude

    Techitude COMMITTEE

    One of my technicians has massive difficulties with maths and always struggles to know how to the interpret molecular weight of a solid chemical and use that to make up different molarity solutions.

    I've made them an easy to understand sheet to use so they can easily work out how much to weigh for what volume and molarity by following the instructions to fill in the quantities.

    Thought it may be of help to others in a similar situation

    Any suggestions for improvements always appreciated :)
     

    Attached Files:

  2. I use free apps on my android phone:
    1. to help making solutions of specific molarity from solids
    https://play.google.com/store/apps/details?id=com.cooloy.SolutionCalculator&hl=en_GB
    2. to make up a specific molarity by diluting a stock solution:
    I use Molarity calculator from Sigma-Aldriche - but has been removed for the android app store - this one seems to do the same thing:
    https://play.google.com/store/apps/details?id=com.carlosemgomes.solutioncalc1&hl=en_GB

    They are both free.
     
  3. Techitude

    Techitude COMMITTEE

    They look great, I would definitely use them but they are too complex for my technician unfortunately hence the paper version :) We're going to leave the filled in ones in a folder so my tech can access them when needed.
     
  4. karen b

    karen b COMMITTEE

    The Cleapss recipe book has this information for lots of different chemicals already worked out for you
     
  5. That's a bit worrying if your technician can't do basic molarities even with the app. Having said that my HOD said her last technician was one of the cleaners and took a pay cut to do the job.
     
  6. Techitude

    Techitude COMMITTEE

    Yes we have those too and they do get used but they sometimes say 'a ten fold dilution of 1M' which my tech cannot work out. They also present the info in quite an overwhelming way for someone who struggles with numbers.

    Think of this situation as something similar.
     
  7. I have a document one of my senior techs gave me many moons ago which shows how to make a molar solution from a solid and also how to dilute a solution. It can be used for any volume and any molarity. I think it's simple enough, but I don't know the level of your technicians difficulties.

    I'll have a go at posting it tomorrow.
     
    Techitude likes this.
  8. I have just nicked your sheet and automated it as I prefer working from a computer (and lazy). Might colour code it by volume later. Thanks a tonne for that
     

    Attached Files:

  9. Techitude

    Techitude COMMITTEE

    Genius!
     
  10. Though not completely accurate for high-level work.:)
     
  11. karen b

    karen b COMMITTEE

    good enough for school use. Given many people here are using tap water to make up solutions a fraction of a gram is not going to make a whole lot of difference
     
    ClaireS, Techitude and CovTech like this.
  12. While true I have been asked to make up solutions that are not in the recipe book
     
  13. I don't like to toot my own horn, I would have also accepted lazy sod!
     
    Techitude likes this.
  14. Techitude

    Techitude COMMITTEE

    I've colour coded this one by molarity. It looks pretty now, which pleases me :D
     

    Attached Files:

    CrowyTech and Peter Sigsworth like this.
  15. Hi @Techitude here is what I use. One really big plus is it can be used for any volume and/or molarity.

    You might need to change the wording to make it user friendly for your tech.

    The list at the bottom is a reminder of mls as part of a litre (e.g. 500mls = 0.5) but I don't tend to use that for my volume element of the equation. I just put in how many mls I want and find it much more straightforward.

    Hope it helps.
     

    Attached Files:

  16. Techitude

    Techitude COMMITTEE

    That's a really good way of doing it. Unfortunately my tech wouldnt be able to comprehend the maths involved but I will print it off for myself and my other tech, we'll definitely use it :) Thanks for sharing.
     
  17. karen b

    karen b COMMITTEE

    Yes, same here. However I suspect if you had a tech not confident in making standard solutions you wouldn't ask them to make up something more complex
     
  18. This sounds like they are not confident with the maths more than the making of solution but I have a minion that's not 100% with solutions so I offer to be an extra pair of hands when she is making them up but I often just sit back and fiddle on my tablet till she is done.
     
  19. Now that is pretty :D
     
  20. It's a shame your tech won't be able to use it.

    I find it so useful, just tap your numbers into a calculator an Bob 's your uncle, quick and easy no complicated formulas needed.