Energy in Bonds
This post will introduce enthalpy for Prelim Chemistry.
Topic: Energy Changes in Chemical Reactions
- Investigate enthalpy changes in reactions using calorimetry and q=mcΔT (heat capacity formula) to calculate, analyse and compare experimental results with reliable secondary-sourced data, and to explain any differences.
Enthalpy refers to the total bond energy of a molecule. Experimentally, you cannot measure the enthalpy directly which is why chemists measure enthalpy through a technique called calorimetry.
This video explores a little more about heat and enthalpy.
Calorimetry is a technique used to measure heat in a chemical reaction.
A form of calorimetry involves measuring heat using a metal calorimeter (basically a metal can) and filling it with a known volume of water. The calorimeter is then covered and a combustion reaction is done underneath the metal can (such as heating with a spirit burner). You measure the change in temperature with a thermometer and use an equation to calculate the heat of enthalpy which will be introduced later.
This video explores calorimetry in a little more depth.
This video shows examples of the equation for q.
This video goes through calorimetry as well, watch this video to reaffirm what you have learnt in the previous videos.