Chapter 3: Chemical Equations & Reaction Stoichiometry

chemical equation

Chemical reactions are just chemical changes

Reactants

A starting material in a chemical reaction

yield

to produce

Products

Ending materials in a chemical reaction.

Law of Conservation of Mass

Matter is neither created nor destroyed in any chemical or physical change

Atomic Theory

The idea that everything is made of small particles

What is a balanced chemical equation?

A balanced chemical equation includes the same number of each kind of atom on both sides of the equation.

What happens if a chemical reaction is not balanced?

If reactions are not balanced, the conservation of matter is violated.

What can change to balance chemical reactions?

The Coefficients

What is a coefficient?

A number placed in front of a chemical formula in an equation

What can never be changed to balance chemical reactions?

The Subscript

What is a subscript?

It is a small number behind an elemental symbol that represents the number of each type of atom in a formula.

What does a chemical reaction give?

The mole ratio of substances

How can the mass of a compound be related to moles?

Molar mass

theoretical yield

The maximum amount of product that can be produced from a given amount of reactant

actual yield

The measured amount of a product obtained from a reaction

percent yield

Indicates how much of the product is obtained from a reaction

percent yield formula

actual yield/theoretical yield x 100

limiting reactant

Any reactant that is used up first in a chemical reaction; it determines the amount of product that can be formed in the reaction

Solution

A homogeneous mixture of two or more substances dissolved in another

Solute

the substance that is dissolved

Solvent

The dissolving agent of a solution

aqueous solution

a solution in which water is the solvent

Percent by mass of solute

mass of solute/mass of solution x 100%

Mass of Solution

mass of solute + mass of solvent

concentration of a solution

% (Weigh/Weigh)

Molarity

The number of moles of solute per liter of solution

Molarity (M)

moles of solute/liters of solution

Dilution of Solution

M1V1=M2V2