Chemical Forums

Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Winga on November 22, 2004, 08:37:43 PM

Title: How can a hotplate heat up a solution?
Post by: Winga on November 22, 2004, 08:37:43 PM

What is the principle of hot plate?

Title: Re:How can a hotplate heat up a solution?
Post by: Mitch on November 22, 2004, 09:09:14 PM

electricity is passed through a metal coil. The resistance creates friction and generates heat.

Title: Re:How can a hotplate heat up a solution?
Post by: limpet chicken on November 22, 2004, 09:11:13 PM

An electrically heated element, under the plate causes the heat, as the current flows though it, there is resistance in the metal heating element, causing the metal to get hot, and consequentially, heating the plate.

If a solution be placed in a beaker or other heat resistant container, then the heat passes by conduction through the containing vessel and heats the solution.

Edit: looks like you got there as I was typing my post Mitch :)

I want a hotplate badly myself, anyone know of a UK supplier, they HAVE to take solo card though, or else I can't order anything :(

Title: Re:How can a hotplate heat up a solution?
Post by: Donaldson Tan on November 23, 2004, 02:00:06 PM

I think a solo cash card is also a maestro. look at the back of the card

Title: Re:How can a hotplate heat up a solution?
Post by: limpet chicken on November 23, 2004, 04:13:50 PM

Thank you, a LOT geo, I never noticed, I rarely use my card other than to withdraw cash LOL, I never even noticed about that on the back :)

That means I should be geting one pound of NaBH4 as soon as I get paid my next money, you have no idea how much I have been looking for that ;D

Title: Re:How can a hotplate heat up a solution?
Post by: pizza1512 on February 03, 2005, 08:56:40 AM

Is radiation made?.



 :animatedwink:

Title: Re:How can a hotplate heat up a solution?
Post by: mithrilhack on February 04, 2005, 12:47:08 PM

There's infrared radiation emitted by the metal yes. But that wouldn't be as much of an effect as the conduction. Seems like a physics question.

Title: Re:How can a hotplate heat up a solution?
Post by: Donaldson Tan on February 04, 2005, 02:16:47 PM

there are 3 modes of heat transfer - convection, conduction and radiation.

if the heating element temperature is below 400C, then the main mode of heat transfer will be conduction. At high temperature, infra-red radiation will be the main mode of transfer. You may make reference to the heat transfer coeefficients of convection, conduction, radiation on any textbook on heat and mass transfer.