[Weber]

Say you had a recipe that called for 91 grams of powdered base "A" dissolved into 200 ml of water.

The second step of this recipe is to add 132 grams(120 ml) of Acid "B" to 50 ml of water.

Third, you are instructed to "heat to 100 degrees celcius", remove from heat, then add the base "A" solution teaspoon at a time to the acid "B" slowly while stirring.

Which would be the right solution to heat? I'm rather inexperienced and am not sure whether to heat the base or the acid. my guess would be the acid so the base will more readily dissolve but thats just my guess


The second problem i have with this recipe is that the derived liquid is too diluted. I'd like for the end result to come out to around 195ml using the same amounts of base and acid. i thought that by modifying the recipe, one could add 91 grams of base to 25ml of water, and continue normally and end up with 195ml total, which would be the concentration I'm looking for... but i don't have any experience to know if this would work.

Any help would be greatly appreciated. Thanks in advance,
-Weber

[Yggdrasil]

My guess would be to heat the solution of base A.  This is because you are given the amount of acid B in units of volume, so the acid is probably a liquid.  In general, acidic liquids (e.g. solutions of mineral acids [HCl, H₂SO₄], or small organic acids [acetic acid]) disolve more easily in water than a some solid bases (e.g. Ca(OH)₂).

[Weber]

Yeah i see what you're saying. So it will be ok to add a near boiling base to a room temp. acid?

[Yggdrasil]

I would think so as long as you follow the teaspoon-by-teaspoon instructions.  It is certainly safer than adding room temp acid to near boiling base. 

(Here, the main issue is that reactions proceed faster at higher temperatures.  When you add a teaspoon of boiling base to a beaker of room temp acid, the resulting solution will have negligibly changed in temp so the reaction will happen at room temperature.  However, if you are adding a teaspoon of room temp acid to a solution of boiling base, the reaction will occur at near 100^oC where the reaction may be more vigorous).

[Weber]

Ahh. i see. Thanks for your help

But i still would like to find a way to get a more concentrated product. any ideas? =/