## Open, Closed & Isolated Systems

Systems Systems refer to any parts of the universe being studied. If you are conducting an experiment in a beaker, then the system you are studying is in the beaker. The system is subject to surrounding factors such as air temperature Read More …

## Enthalpy Change Calculation

Example: Propane Combustion When (0.5g) of propane is burned, the heat produced is used to raise the temperature of (100cm3) of water from (20°C to 40°C), calculate the enthalpy change for the reaction. In this example, you are Read More …

## Enthalpy, Entropy & Gibbs Free Energy

Enthalpy  Entropy Gibbs Free Energy       Enthalpy is the amount of heat energy transferred (heat absorbed or emitted) in a chemical process under constant pressure. Entropy measures the amount of heat dispersed or transferred during a chemical process. Gibbs Read More …

## Enthalpy

WHAT IS ENTHALPY CHANGE? Don’t get hung up with the term enthalpy change. It is just a simple term to denote the amount of heat that passes in or out of a system during a chemical reaction under constant pressure. Read More …

## Hess Law

WHAT IS HESS LAW? Hess law states that energy change in the overall chemical reaction is the sum of energy change or enthalpy change in the individual reactions that comprises it. Hess’ Law can be difficult to understand because of all the Read More …

## Hess Law – Calculation for Methane formation

METHANE GAS – CH4 What is the enthalpy change when methane is formed using carbon graphite and hydrogen? When a chemical reaction takes place, heat is either given off or absorbed. If given off, it is called an exothermic reaction. Read More …

## Gibb’s Free Energy – Ammonia

In the question above, you are asked to calculate Gibb’s Free Energy for the Haber Process. The Haber Process is a process of manufacturing ammonia in a factory. The raw materials are nitrogen and hydrogen. Nitrogen is obtained by burning Read More …

## Understanding Gibbs Free Energy

What is Gibbs Free Energy? For a simple definition, Gibbs free energy can be described as A measure of the amount of energy available to do work. Gibbs free energy is used in chemistry to help determine and predict ahead Read More …

## Reaction Spontaneity

(Picture above – Dog escaping over the fence – winter 2015) A spontaneous process is a physical or chemical change that occurs with no outside intervention. In life, many things happen spontaneously. For example, my dog escaped over the fence Read More …

## Entropy

WHAT IS ENTROPY? Entropy refers to the amount of unusable energy in a system When water flows over a dam, it looses some of its useful energy. Solid wood burns to become ash. Ice melting. Converting the useful energy to Read More …