pH Levels and Chemical Reactions Review

Flashcards covering pH levels of common substances, fundamental chemical reaction concepts, and the six major types of chemical reactions including Combination, Decomposition, Single Replacement, Double Replacement, Combustion, and neutralization.

Acid (pH Range)

A substance with a pH level less than $7$. Examples include Tomato Juice (pH $4$), Gastric Juice (pH $1$), Vinegar (pH $3$), and Black Coffee (pH $5$).

Base (pH Range)

A substance with a pH level greater than $7$. Examples include Blood (pH $8$), Baking Soda (pH $9$), Hand Soap (pH $10$), Ammonia Solution (pH $11$), and Bleach (pH $12$).

Neutral

A substance with a pH level of exactly $7$, such as Water.

Chemical Reaction

A process where substances (reactants) change into new substances (products) with different properties through the rearrangement of particles.

Reactants

The starting substances that are mixed together in a chemical reaction.

Products

The new substances that result from a chemical reaction among the reactants.

Evidence of Reaction

Signs that a chemical change has occurred, including color change, evolution of gas (bubbles), formation of a precipitate (solid), temperature change, or odor change.

Law of Conservation of Mass

A principle stating that the total mass of reactants must equal the total mass of products, as atoms are not created or destroyed, only rearranged.

Combination (Synthesis) Reaction

A reaction where two or more substances join together to form one new substance, following the general form $A + B \rightarrow AB$.

Decomposition Reaction

A reaction where one compound breaks apart into two or more simpler substances, following the general form $AB \rightarrow A + B$.

Single Replacement Reaction

A reaction where one element replaces another element in a compound, following the general form $AB + C \rightarrow AC + B$.

Double Replacement Reaction

A reaction where two compounds exchange parts (ions) to form two new compounds, following the general form $AB + CD \rightarrow AC + BD$.

Combustion Reaction

A chemical reaction in which a fuel reacts with oxygen ($O_2$) to produce carbon dioxide ($CO_2$), water ($H_2O$), and energy in the form of heat and light.

Acid-Base (Neutralization) Reaction

A specific type of double displacement reaction where an acid reacts with a base to produce salt and water, reducing the acidic and basic properties of the reactants.

Precipitate

A solid substance that forms and settles out of a liquid mixture during a chemical reaction.

Rust (Iron Oxide) Formation

A combination reaction where iron reacts with oxygen and moisture in the air: $4Fe + 3O_2 \rightarrow 2Fe_2O_3$.

Electrolysis of Water

A decomposition reaction where electrical energy is used to break down water into hydrogen and oxygen gases: $2H_2O \rightarrow 2H_2 + O_2$.

Photosynthesis

A process where carbon dioxide and water react in the presence of light energy to produce glucose and oxygen: $6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2$.

Cell Respiration

A decomposition process where glucose and oxygen react to produce carbon dioxide, water, and energy (ATP): $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy (ATP)}$.

Methane Combustion

The burning of methane in oxygen to produce carbon dioxide, water, and energy: $CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O + \text{Energy}$.