Question

Can anybody explain to me how to determine the endormicity and exormicity in a reaction and where does the equilibrium shift. Pls. give an example of it. Iwas reading my book and trying to understand but i really can't comprehend it. Now I'm stuck here i can't answer my post lab experiment. Pls anybody thanks. Just a simple explanation please.

Answer 1

It ALWAYS helps if you give us an example and let us show you how to do it. Our examples may not fit your needs.
A + B ==> C delta H = -235 kJ.
This reaction has a - delta H; that means it is EXOTHERMIC. I prefer to rewrite the equation this way.
A + B ==> C + heat.

Le Chatelier's Principle, in very simple language, tells us that a system in equilibrium will try to undo what we do to it. Suppose then that we add heat to the reaction. It will try to undo that meaning it will try to get rid of the extra heat we've added. How can it do that? (There are only three choices; i.e., shift to the right, shift to the left, neither). To get rid of the heat C reacts to produce A + B BECAUSE that uses the heat we have added (meaning that the reaction shifts to the left). Or if we lower the temperature, the
reaction tries to undo that by producing heat. How can it produce it. Of course by A + B ==> C gives us heat.

For endothermic reaction delta H is +. If we have
X + Y = Z and delta H = +285 kJ, I prefer to rewrite it as
X + Y + heat = Z.

Answer 2

In our experiment they gave us this eguilibrium to investigate:
H2CO3(aq)=H2O(l)+CO2(g)
We put soda in a syringe when we push the plunger (increase pressure) there was less bubbles formed but when we pulled the plunger (decrease the pressure) the was more bubbles formed. With this observation and on the equation how will i be able to determine or where will i be able to base the thermicity endothermic or exothermic of equation. Pls. DrBob222 need an answer, thanks.