Unit 6 - Chemical Equations Flashcards
Symbols used in writing chemical equations
Definition of a balanced chemical equation:
no atoms are lost or gained
the number of reacting atoms is equal to the number of product atoms
Law of Conservation of Mass
Mass is neither created or destroyed during a chemical reaction - it is conserved.
Mass Reactants = Mass Products
Subscript
Small numbers to the lower right of chemical symbols. Represent the number of atoms of each element in a molecule.
O₂
Coefficients
The large numbers in front of chemical formulas. Represents the number of molecules of the substance.
2Al
Diatomic Molecules
If these elements appear by themselves in an equation, the must be in pairs with the subscript 2.
(H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂)
Reactants
Substances being mixed in a chemical reaction. The left side of the equation.
Products
Substance(s) being made. Right side of the equation.
Synthesis or Combination
Two or more elements combine to make one product.
A + B –> AB
Decomposition Reaction
One reactant breaks down into two or more elements.
AB –> A + B
Single Replacement
An element and a compound are located on each side of the equation. The element on the reactant side switches with the similarly charged ion within the compound on the reactant side.
A + BC –> AC + B
Double Displacement
There are two compounds on each side of the equation. During a DD Reaction the positively charged cations in each compound switch places. Also known as Precipitate Reaction.
AB + CD –> AD + CB
Precipitate
Formation of a solid in a solution.
Combustion
Any compound formed from only Carbon an Hydrogen (fuel) added to Oxygen to produce Carbon Dioxide and Water.
Predict the products and write a balanced equation from the following word statement:
Methane (CH₄) plus Oxygen Gas forms:
How to PREDICT PRODUCTS of the 4 Main Types of Chemical Reactions.
Predict the products of and write a balanced equation from the following word statement:
Methane (C3H8) reacts with Oxygen gas to form __________.
