- Feb 23, 2021
Lol, no I know how it works. Remember though: melting point is a range, but I guess it depends on how accurate and traditional you want to be about your lab notes & such.You don't need a capillary tube... The material to be tested is sprinkled on the top of the block.
material to be tested is sprinkled on the top of the block, a thermometer is inserted in the slanted hole, and the block is heated from below by a Bunsen burner or other heat source. As soon as the material starts to melt, read the thermometer for the melting point.
I've seen others sell the block for $80 just the block so I think all considered not bad. https://www.wardsci.com/store/product/8887436/simple-melting-point-apparatus ... https://us.vwr.com/store/product/8887436/simple-melting-point-apparatus . a 3 inch block on ebay is about that much anyways and I don't wanna hassle drilling a hole.
Yes I can use an old tin can and thermometer but I imagine the flame being to close to such thin aluminum be a pain to keep the surface temp slow/ accurate. All together it really isnt that much. If I wanted to go cheap I would use a plat on top with a pot and cooking oil with an electric thermometer for $10 but I'm not gonna go that cheap
Also, a capillary packs the sample down into one cohesive mass, and this makes observing its phase-change-start and -end temps less ambiguous, don't you think? Or is that not a problem with these heavy-ass bean cans?
A $1 capillary in a $6 test tube + oil bath on your stove = low profile. Get an infrared thermometer for ~$15 on Amazon. So what's that like $22? It's basically the same price.
Of for ~$10 you can get a Thiele-type, triangle-shaped, melting-point tube. There are no wrong answers here, of course, and I'm not knocking the bean cans – indeed it's a pretty cool, simple rig. I'm just wondering how accurate do you think they are? Probably pretty close, right? Thermodynamics is … tricky, to say the least.