Page 1 of 1

Temperature

Posted: Wed Jan 29, 2020 10:19 am
why does adding heat to an exothermic reaction drive it the other way?

Re: Temperature

Posted: Wed Jan 29, 2020 10:32 am
Think about an exothermic reaction as heat produced on the products side of the reactants. If you increase the amount of heat in the system, then the reaction will be driven to the other way in favor of the reactants because in order to remove heat from the system by Le Chatelier's Principle, the reverse reaction (which is endothermic) must be enacted.

Re: Temperature

Posted: Wed Jan 29, 2020 10:48 am
Say A->B is exothermic, meaning that B is a lower energy state than A.

B is therefore more stable to have, since it is lower energy meaning that the reaction will spontaneously go towards B (until it reaches equilibria)

The less stable A requires more energy to be maintained. So if you add more heat you are adding more available energy for the reaction to use meaning it can afford to make more of the less stable stuff.

Re: Temperature

Posted: Wed Jan 29, 2020 11:13 am
Heat is part of the products in an exothermic reaction. If the temperature is raised, there is more heat and the reaction is driven back to maintain equilibrium.

Re: Temperature

Posted: Wed Jan 29, 2020 12:37 pm
In an exothermic reaction, heat is exuded once the reaction runs. It is emitted from the reaction proceeding, so you can almost consider it a product of the reaction itself. Thus, if we want to maintain equilibrium in a system, adding more of this product (adding heat/ increasing the temperature) will simply drive the reaction to proceed in the opposite, lacking direction.

Re: Temperature

Posted: Wed Jan 29, 2020 3:33 pm
So is an ice cube melting an example of an exothermic or endothermic reaction? Because the temperature of the water final is greater than the initial temperature and the difference would therefore be positive is it an endothermic reaction?

Re: Temperature

Posted: Wed Feb 05, 2020 7:06 pm
It's endothermic reaction since the ice cube needs to absorb heat for the melting process to occur.

Maya Beal Dis 1D wrote:So is an ice cube melting an example of an exothermic or endothermic reaction? Because the temperature of the water final is greater than the initial temperature and the difference would therefore be positive is it an endothermic reaction?