key term - Law of Conservation of Mass

Definition

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction, meaning the total mass of the reactants must equal the total mass of the products. This principle underpins many concepts in chemical engineering, emphasizing that all materials in a system must be accounted for in any process. Understanding this law is crucial when performing calculations to ensure that mass balances are maintained throughout chemical processes.

5 Must Know Facts For Your Next Test

1. The law was first formulated by Antoine Lavoisier in the late 18th century, revolutionizing chemistry by establishing that reactions do not change the total mass.
2. In practical applications, any discrepancy in mass during experiments can indicate measurement errors or unaccounted reactions.
3. The law applies to both chemical reactions and physical processes, ensuring that all inputs and outputs are balanced.
4. When performing material balance calculations, it is essential to correctly identify inflows and outflows to maintain adherence to the law.
5. In chemical engineering, the law of conservation of mass serves as a foundational principle for designing and optimizing processes like reactors and separators.

Review Questions

• How does the law of conservation of mass apply when analyzing a closed system?
  • In a closed system, the law of conservation of mass implies that the total mass remains constant because no mass can enter or leave. This means that all reactants and products must be accounted for within that system. When performing calculations, engineers use this principle to ensure that all inputs match the outputs, allowing for accurate predictions about how processes will behave over time.
• Discuss the importance of stoichiometry in relation to the law of conservation of mass in chemical reactions.
  • Stoichiometry is critical because it uses the law of conservation of mass to relate the quantities of reactants and products involved in chemical reactions. By applying this law, chemists can determine how much of each reactant is needed to produce a desired amount of product while ensuring that no mass is lost in the process. This understanding helps engineers design more efficient reactions and minimize waste in industrial applications.
• Evaluate how the law of conservation of mass influences material balance calculations in chemical engineering practices.
  • The law of conservation of mass is fundamental to material balance calculations as it requires engineers to ensure that all input and output masses in a process are equal. This evaluation allows engineers to track materials through processes, identify inefficiencies or losses, and optimize systems accordingly. By applying this principle, engineers can develop reliable models that reflect real-world operations, leading to improved design and operational efficiency across various chemical engineering applications.

Related terms

Closed System:

A closed system is one where mass cannot enter or leave, allowing for the application of the law of conservation of mass in analyzing processes within that system.

Stoichiometry:

Stoichiometry involves the calculation of reactants and products in chemical reactions, relying on the law of conservation of mass to determine the relationships between different substances.

Mass Flow Rate: Mass flow rate is a measure of the mass of a substance passing through a given surface per unit time, and it is essential for performing material balances in engineering applications.