Energetics

I learn on how to use the energy cycle in finding out the various enthalpy changes in a balanced equation. However i m still a little unsure about it. It is really new for me n so i m getting use to it.

The enegry level diagram/ Born Haber Cycle is somthing interesting . At first it was diffcult, after my chemistry teacher explained and went throught a few examples on how to draw the diagram i know how to do it. All the postive enthalpy changes which is the endothermic reaction all point upwards while all the negative enthalpy changes which is the exothermic reaction all point downwards

Energetics

From the energetics part 1 worksheet, I learn that there are 10 different enthalpy changes. This topic is a new topic to me as i was from the normal acadamic stream taking the old syllabus.

For almost all the enthalpy changes, there is a set of standard conditions to measure it.

Temperature: 298K (25 degree celsius)
Pressure: 1 atm
Concentration (when dealing with solutions): 1 mol dm-3

I also learned about hess's law

Hess law states that the enthalpy changes for a chemical reaction is the same, regardless of the route taken, provided that the inital states of the reactants and the final states of the products are the same

chemistry

I learn that if the 1st element is greater than one have to indicate the identity of the subscript using one of the prefixes
example: 2-di
3-tri
4-tetr

i also learn that water n ammonia are binary compounds


Binary covalent compounds can be reconginse from their formulas which contain symbols
for only two non metallic elements