Re: Safe Exothermic Reactions??

michael.juska@xxxxxxxxx wrote:
> Hey, I am trying to find if there is an exothermic reaction
> between two liquids that gives off a fair amount of heat 100~200F which
> is environmentally friendly. Does anyone know of anything that can do
> this? I appreciate the help.
>
> Mike

Hmm. The high end of your range doesn't really fit under the criteria
of "safe", now does it? If you're talking about a reaction in aqueous
media, a temperature rise of 200 Farenheight is like saying, "Can I mix
to liquids that instantly send the temperature from just melted ice to
almost boiling?" That's pretty far.

Maybe you'll like the suggested NaOH + HCl reaction, what with the
product being common salt water. But I don't think you'll get
noticeable warmth from a dilute starting solution. You need preety
strong concentraions of starting reactants, and they are at least a
little dangerous.

Also, the more water you have, the more reactants you'll need. Water
has a high heat capacity. The more water there is, the more energy
required to raise its temperature.

Furthermore, if you intend your water mix to be some sort of portable
heat source (someone once needed to warm his biodeisel fuel with a
cheap, safe, reaction) then you'll need even more to account for heat
loss in the transfer from vessel to vessel.

.

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