Chapter 3: Chemical Reactions Flashcards
What is Chemical Reaction?
When 1 or more substances change to create different substances.
What is Reactants?
Substances which undergo a chemical reaction.
What is products?
Substances created in a chemical reaction.
What are 5 Evidences of a Chemical Change?
- Energy Change: Temperature Change (Thermal Energy released or absorbed), emission of light (light energy released) emission of sound, electrical energy
- Odour Change
- Colour Change
- Formation of a Gas: Gases are created in some chemical reactions. When the reaction takes place in a solution, you can notice the gas being created as bubbles in the solution.
- Formation of a Solid (Precipitate): In some reactions that take place in solution, a substance is created that is not soluble in the solution. The substance comes out of solution as a solid (precipitate).
What is a Precipitate?
An insoluble solid which is created in a chemical reaction that hapens in solution.
What is an Exothermic Reaction?
A reaction that releases energy, forming chemical bonds.
What is an Endothermic Reaction?
A reaction that absorbs energy, breaking chemical bonds.
What is the Law of Conservation of Energy?
Energy can be converted from 1 form to another, however the total energy of the universe stays constant.
What is the Law of Conservation of Mass?
The law stating that matter cannot be formed or destroyed during a chemical reaction.
What is a Closed System?
A system where no transfer of matter occurs between system and surroundings.
What is a Open System?
An exchange of matter among system and surroundings.
What is the formula for #of moles?
n = m (mass) / M (molar mass)
What is the formula for mass?
m = n (#of moles) x M (molar mass)
What is the General Form for Formation?
X + Y = XY
What is the General Form for Decomposition?
XY = X + Y
