Chemistry Reaction and Equilibrium Concepts

Flashcards covering key chemistry concepts related to reactions, equilibrium, and functional groups.

Exothermic reaction

A reaction that releases heat to the surroundings.

Endothermic reaction

A reaction that absorbs heat from the surroundings.

Activation energy

The difference in energy between the reactants and the maximum energy (energy barrier) needed for a reaction to occur.

What does NOT affect reaction rate?

Spontaneity of the reaction.

Factors that affect reaction rate

Force of collisions, number of collisions, activation energy, and orientation of molecules.

Effect of lowering temperature on reaction rate

Decreases reaction rate because particles move slower and collide less effectively.

Effect of increasing concentration on reaction rate

Increases reaction rate because there are more collisions between particles.

Effect of adding a catalyst on reaction rate

Increases reaction rate by lowering activation energy.

Which factor decreases reaction rate?

Lowering the temperature.

Which factors increase the rate of a reaction?

Increasing temperature, removing products, adding a catalyst.

Which process is NOT reversible?

Cutting down a tree.

What characterizes chemical equilibrium?

Reactants and products are formed at the same rate.

Equilibrium expression for A + 2B ⇌ 2C + D

K = [C]²[D] / [A][B]².

For K = 4.6 × 10⁻¹⁵, which side is favored?

The left; small (reactants favored, very little product).

H₃O⁺ ion name

Hydronium ion.

Products of an acid-base reaction

Salt and water.

Bronsted-Lowry acid

Donates protons (H⁺).

Bronsted-Lowry base

Accepts protons (H⁺).

Bronsted acid in HCIO₄ + H₂O ⇌ CIO₄⁻ + H₃O⁺

HCIO₄.

Strongly basic pH

11.5.

Neutral pH

7.

Weakly acidic pH

5.3.

[H⁺] when pH = 5.45

3.55 × 10⁻⁶ M.

pH when [H₃O⁺] = 5.9 × 10⁻³ M

≈ 2.23.

Buffer solution

Resists changes in pH (closely maintains original pH).

Functional group without oxygen

Amine.

Functional group of R–CHO

Aldehyde.

Functional groups in lactic acid

Carboxylic acid and alcohol.

Name: 3-ethyl-3-methylpentane

Branched alkane with ethyl and methyl substituents on carbon 3.

Name: 4-ethyl-3,3-dimethylheptane

Branched alkane with ethyl and two methyl groups.