[firzzy87]

we are always add acid to water ... Is it will be the same as i add water to acid .. i've tried b4 .. and simply mistake happen as my hand got hurt bcoz the solution cbecomes hot .. can we reverse?? If not why

this might be the easiest one , but i can't find how to solve it ..
Why doesnt matter how much water i add when dissolve the acid or when carrying out the titration? Isn't the acid will still same dissolve finally??

Thank yuou..



 

[profmsg]

ADDING ACID TO THE WATER IS TOTALLY DIFFERENT THAN ADDING WATER TO ACID. WHEN YOU ADD ACID TO WATER, YOU ARE DILUTING. THERE ARE LOTS OF WATER MOLECULES FOR ACID MOLECULES. SO ACID MOLECULES ARE NOT COMPETING FOR WATER MOLECULES. WHILE IN REVERSE CASE, LOTS OF ACID MOLECULES ARE COMPETING FOR LITTLE AMOUNT OF WATER MOLECULS WHICH GENERATES HEAT.

REMEMBER THAT,,,, ACID MOLECULES ARE ACTIVE MOLECULES WHICH HAS HIGH AFFINITY FOR WATER MOLECULES.

[ARGOS++]

Dear Firzzy87,

The Heatcapacity! of Water is the Key for the answer to your question!

As you may know, Water has the highest Heatcapacity of all we know, - that means, that Water can store the highest Heat-energy, till its Temperature increases by one. But on the other side it has a quite low boilingpoint!
Additionally most Heat is released during dilution on the top end of the concentration scale for the acid and not on the lower end.

Quintessence:    When you start to add  Water, you add a small amount of Heatcapacity, but you generate a lot of Heat, what results in a fast and high increase of the Water-temperature.
The result is known by your hand!!  - The other way around you may think by yourself!

I hope it may be of help to you too!

Good Luck!
                    ARGOS⁺⁺

[AWK]

Practically the rule "add acid to water" is in fact an unique exception, but because H2SO4 is a one of a few common acids, and a breaking of this rule can be extremely dangerous, it is convenient to treat this rule unconditionally.