Rates of Reaction and Reversible Reactions Vocabulary

This set of vocabulary flashcards covers key terminology and concepts from Chapter 8 (Rates of Reaction) and Chapter 9 (Reversible Reactions), including collision theory, Le Chatelier's principle, and experimental measurement techniques.

Rate of Reaction

A measure of how fast the reactants are changed into products in a chemical reaction.

Collision Theory

The theory stating that chemical reactions occur when particles collide with sufficient energy, and that the rate depends on collision frequency and energy transferred.

Activation Energy

The minimum amount of energy that particles must have in order to react when they collide.

Catalyst

A substance that increases the rate of a chemical reaction by providing an alternative reaction pathway with a lower activation energy, without being changed or used up.

Enzymes

Biological catalysts found in living systems.

Mean Rate of Reaction

Calculated using the formula: $\text{Mean rate of reaction} = \frac{\text{Quantity of reactant used or product formed}}{\text{Time}}$.

Turbidity

The cloudiness of a solution, often used as a measure of the rate in reactions that produce a precipitate.

Precipitate

A solid that is formed in a solution during a chemical reaction.

Tangent

A straight line drawn on a rate graph that touches a curve at a particular point to determine the gradient and rate of reaction at that specific time.

Gradient

The steepness of a line on a graph, calculated as $\frac{\text{change in y}}{\text{change in x}}$, which represents the rate of reaction.

Reversible Reaction

A chemical reaction where the products can react to re-form the original reactants, represented by the double arrow symbol $\rightleftharpoons$.

Equilibrium

The state reached in a closed system when the forward and reverse reactions occur at exactly the same rate and the concentrations of reactants and products remain constant.

Closed System

A reaction vessel where none of the reactants or products can escape and no external substances can enter.

Le Chatelier's Principle

The principle stating that if the conditions of a reversible reaction at equilibrium are changed, the system will react to counteract that change by shifting the position of equilibrium.

Anhydrous

A term describing a substance that is without water, such as the white powder formed after heating hydrated copper sulfate.

Hydrated

A term describing a substance that contains water, such as blue copper sulfate crystals.

Endothermic Reaction

A reaction that absorbs energy from the surroundings.

Exothermic Reaction

A reaction that transfers energy to the surroundings.