Chemical Reactions and Mass Balance

Law of Conservation of Mass: Matter cannot be created or destroyed in a chemical reaction, only transformed from one substance to another.
Mass Balance Equation: Input (reactants) = Output (products) + Accumulation (in a closed system)
Applications: Useful in designing and optimizing chemical reactions, reactors, and processes.

Chemical Equation: A symbolic representation of a chemical reaction, where reactants are on the left and products are on the right.
Reactants: Substances that undergo a chemical change to form products.
Products: Substances formed as a result of a chemical reaction.
Stoichiometry: The study of the quantitative relationships between reactants and products in a chemical reaction.

Antoine Lavoisier: A French chemist who discovered the role of oxygen in combustion and respiration.
Oxygen's Role: Lavoisier showed that oxygen is necessary for combustion and respiration, and that it supports life.
Calorimeter: Lavoisier developed an apparatus to measure heat changes during chemical reactions, laying the foundation for thermochemistry.
Modern Chemical Nomenclature: Lavoisier developed a systematic method for naming chemical compounds, which is still in use today.

Matter cannot be created or destroyed in a chemical reaction, only transformed from one substance to another.
The mass balance equation states that input (reactants) equals output (products) plus accumulation (in a closed system).
Mass balance is useful in designing and optimizing chemical reactions, reactors, and processes.

A chemical equation is a symbolic representation of a chemical reaction, with reactants on the left and products on the right.
Reactants are substances that undergo a chemical change to form products.
Products are substances formed as a result of a chemical reaction.
Stoichiometry is the study of the quantitative relationships between reactants and products in a chemical reaction.

Antoine Lavoisier was a French chemist who discovered the role of oxygen in combustion and respiration.
Oxygen is necessary for combustion and respiration, and it supports life.
Lavoisier developed a calorimeter to measure heat changes during chemical reactions, laying the foundation for thermochemistry.
Lavoisier developed a systematic method for naming chemical compounds, which is still in use today, known as modern chemical nomenclature.

Increasing concentration of reactants increases reaction rate due to more collisions between molecules
Raising temperature increases reaction rate by providing more kinetic energy for molecules to collide effectively
Increasing surface area of reactants increases reaction rate by providing more sites for collisions to occur
Presence of catalysts increases reaction rate by lowering activation energy

Reactant molecules must collide with sufficient energy and correct orientation for reaction to occur
Increasing temperature increases kinetic energy, allowing more successful collisions to occur

Energy barrier that must be overcome for reaction to occur
Raising temperature provides more energy for reactants to overcome activation energy, increasing reaction rate

State in which forward and reverse reactions occur at equal rates, with no net change in concentrations of reactants and products
Equilibrium constant (K) is the ratio of concentrations of products to reactants at equilibrium
Equilibrium constant (K) depends on temperature, but not on initial concentrations

If a system at equilibrium is subjected to a change, the equilibrium will shift to counteract the change
Examples of changes that can affect equilibrium include changes in concentration, temperature, or pressure

Definition: a substance that increases reaction rate without being consumed or altered
Catalysts work by lowering activation energy, allowing more molecules to react
Homogeneous catalysts are present in the same phase as reactants, while heterogeneous catalysts are present in a different phase
Characteristics of catalysts include high surface area, high reactivity, and remaining unchanged after reaction
Examples of catalysts include enzymes in biological reactions and metals in industrial processes

Reaction rate is the speed at which a chemical reaction occurs, and it is affected by several factors, including:
- Concentration of reactants, which increases reaction rate when increased
- Temperature, which increases reaction rate when increased
- Surface area of reactants, which increases reaction rate when increased
- Presence of catalysts, which increases reaction rate
Rate equation is a mathematical expression that describes the rate of a reaction, typically expressed in terms of concentration of reactants and products, and may include rate constants and order of reaction.

A catalyst is a substance that increases the rate of a chemical reaction without being consumed or altered in the process, and it has the following characteristics:
- Not consumed or altered during the reaction
- Increases reaction rate
- Lowers activation energy
- Can be reused
There are two types of catalysts:
- Homogeneous catalysts, which are present in the same phase as the reactants
- Heterogeneous catalysts, which are present in a different phase than the reactants
Examples of catalysts include:
- Enzymes in biological reactions
- Metals in industrial reactions

Equilibrium constant (K) is a value that describes the ratio of the concentrations of products to reactants at equilibrium, and it has the following characteristics:
- Independent of initial concentrations
- Dependent on temperature
- Related to the Gibbs free energy change (ΔG) of the reaction
There are two types of equilibrium constants:
- Kc, which is the equilibrium constant in terms of concentration
- Kp, which is the equilibrium constant in terms of pressure
Importance of equilibrium constants lies in their ability to:
- Predict the direction of a reaction
- Determine the extent of a reaction
- Relate to the spontaneity of a reaction