Molarity

Mixture

A sample of matter containing two or more substances that are physically combined but not chemically bonded.

Pure Substance

A sample of matter that contains only one type of element or compound with a fixed composition.

Relative Composition

The proportional amounts of different components in a mixture, which determine the mixture’s properties.

Alloy

A mixture of metals (or a metal with nonmetals) whose composition determines properties such as strength and corrosion resistance.

Solution

A homogeneous mixture in which the composition and properties are uniform throughout the entire volume.

Homogeneous Mixture

A mixture that has the same composition and properties at every point within the sample.

Solvent

The component of a solution present in the greatest amount, acting as the medium in which other substances are dissolved.

Aqueous Solution

A solution in which water is the solvent.

Solute

A component of a solution that is present in a smaller amount than the solvent.

Concentration

A measure of the relative amount of a given component in a solution.

Dilute Solution

A solution containing a relatively small amount of solute compared to the solvent

Concentrated Solution

A solution containing a relatively large amount of solute compared to the solvent

Molarity (M)

A concentration unit defined as the number of moles of solute per liter of solution.

M = mol solute/L solution

Molarity Formula

Dilution

The process of decreasing a solution’s concentration by adding solvent, without changing the amount of solute.

Stock Solution

A concentrated solution that is diluted to prepare solutions of lower concentration

Effect of Dilution

Dilution increases solution volume while keeping the number of moles of solute constant.

Moles–Molarity Relationship

The number of moles of solute in a solution equals the product of molarity and volume (in liters).

n = ML

Moles–Molarity Relationship Equation

M1 L1 = M2 L2

Dilution Equation: A relationship showing that the amount of solute before and after dilution remains constant.

C1 V1 = C2 V2

General Dilution Equation: A more general form that applies to any concentration unit.

Guard Digit

A non-significant digit retained in intermediate calculations to prevent rounding errors in the final result.

Rounding Error

An error introduced when intermediate results are rounded too early during calculations.

Single-Step Calculation Method

A method that avoids intermediate rounding by performing the calculation in one step and rounding only the final answer.

Acetic acid

• A molecular compound commonly found in vinegar.

• CH₃CO₂H