Lab equipment

Quote: Originally posted by Sulaiman

I have no idea how reliable the hotplate-stirrer that you pointed to is, but it is popular so you can assume that parts will be available for a while. / waffle on __________________________________________________________ 'which car (automobile) is best' ? ... 'horses for courses'. I think that no matter what heating facilities we have, a cheap generic hotplate is always useful, so I suggest that you start with one. After a while you will know exactly what you want. (and after another while you will want something else again). If you are already at this stage then; I can imagine someone needing only that hotplate-stirrer for many years, and others getting quickly frustrated. For boiling water in a beaker to reduce volume or increase concentration, or in a flask for for a distillation, due to general heat losses, very roughly, evaporated water ml/hour = Watts rating of heater. e.g. a 300W hotplate would boil water off at 300 ml/hour ... roughly. (Theoretically 300/2257 = 0.133 g/s. ... 478.5 ml/hour) If jointed glassware is going to be used then I consider 300W to be too much for 10/19 and too little for 24/29. It depends upon what type of chemistry you want to do, and at what scale, and cost. __________________________________________________________/ waffle off [Edited on 1-11-2018 by Sulaiman]

Thanks for the info, I haven't found any other heater stirrers in this price range, the good brands's heater stirrers are located in the US and cost double for them to be shipped to Europe where I am at right now.

Quote: Originally posted by gatosgr

https://www.ebay.com/itm/SH-3-Hot-Plate-Magnetic-Stirrer-Mix... [Edited on 6-11-2018 by gatosgr]

Quote: Originally posted by j_sum1

Quote: Originally posted by gatosgr   https://www.ebay.com/itm/SH-3-Hot-Plate-Magnetic-Stirrer-Mix... [Edited on 6-11-2018 by gatosgr] Sold Out. (and does not post to oz. sniff.)

Quote: Originally posted by gatosgr

Quote: Originally posted by j_sum1   Quote: Originally posted by gatosgr   https://www.ebay.com/itm/SH-3-Hot-Plate-Magnetic-Stirrer-Mix... [Edited on 6-11-2018 by gatosgr] Sold Out. (and does not post to oz. sniff.) found this for you https://www.ebay.com/itm/Top-Plate-Magnetic-Stirrer-SH-3-Hot...

Quote: Originally posted by gatosgr

Has anyone found a descent scale? Not a microgram scale. 1kg range. [Edited on 7-11-2018 by gatosgr]

Quote: Originally posted by Sulaiman

Quote: Originally posted by gatosgr   Has anyone found a descent scale? Not a microgram scale. 1kg range. [Edited on 7-11-2018 by gatosgr] I have two cheap eBay small scales, 300g x 0.01g and 2000g x 0.1g what ever type of digital scales you buy, they will need calibration. High-end scales often have inbuilt standards, the three 100g calibration weights for my 300g scales cost slightly more than the scales themselves, my cheap 2kg scales are effectively useless for 'scientific' purposes as the required calibration weights are too expensive for me. So, for 1 kg I suggest that you just use commercial or kitchen scales. (unless you can afford the calibration weight or a regular calibration service) P.S. As even cheap digital scales are reasonably linear, and give repeatable performance for a period of time, If all measurements are in weight, using one linear weighing device then all relative ratios will be accurate, This includes stoichiometric starting ratios of reactants, solvent ratios, product yield efficiency etc. So if you only use one machine for weighing and everything is measured by weight, you can calculate results as if the scales were calibrated/accurate. Using more than one measuring device invalidates the relationships / ratios. [Edited on 10-11-2018 by Sulaiman]