Engineering Chemistry Exam Answers: Lubrication, Water Treatment, and Materials
Here are clear, step-by-step answers for all the questions shown in your paper.
Q1 (6): Hydrodynamic Lubrication Concept
Hydrodynamic Lubrication – Concept
Hydrodynamic lubrication is a type of lubrication in which a thick film of lubricant completely separates two moving surfaces.
Mechanism (Step-by-Step):
- When two surfaces move relative to each other, a wedge-shaped film of lubricant is formed.
- The moving surface drags lubricant into the gap.
- Pressure is developed inside the lubricant film.
- This pressure
Chemical Process Mass Transfer Principles Explained
Chemical Process Mass Transfer Principles
Mass transfer in chemical technology processes can be categorized:
- With exchange of several different components.
Absorption Equilibrium State
In the theoretical absorption equilibrium state between contacted liquid and gas phases:
- The same mass streams of substance(s) are transported to and from each of the phases.
System Dynamics
A system arranged to be in a nonequilibrium state naturally strives for:
- Reaching the equilibrium state corresponding to present conditions.
Understanding Chemical Reactions: Types and Equations
Chemical Reactions Defined
A chemical reaction is a process in which one or more substances, known as reactants, undergo a transformation to form new substances with different chemical properties, known as products. During a chemical reaction, the arrangement of atoms in the reactants changes, leading to the creation of new bonds and the breaking of old ones. Chemical reactions are fundamental to understanding how matter interacts and changes in the world around us.
For example, hydrogen gas combines
Read MoreMass Transfer Principles in Industrial Processes
Interphase Mass Transfer Concepts and Statements
The following is the corrected and proofread version of the original multiple-choice statements. All original content and option letters have been preserved while spelling, grammar, and capitalization have been corrected for clarity and SEO.
- 1. Mass transfer in specific industrial conditions may be: b. with no exchange of several different components.
- 2. In strictly theoretical absorption equilibrium conditions between the contacted liquid and gas environments:
Chemical Composition, Formulas, and the Mole Explained
Compounds Display Constant Composition
Another indicator that can be used to distinguish compounds from mixtures is the proportions of elements.
Law of Constant Composition
The law of constant composition: All samples of a given compound have the same proportions of their constituent elements. Water will always have 1 oxygen for every 2 hydrogen atoms (H2O).
Chemical Formulas: How to Represent Compounds
Chemical formula
Chemical formula: Indicates the elements present in a compound and the relative number
Read MoreChemical Bonding, Polarity, Reactions and Intermolecular Forces
Endothermic Reactions
An endothermic reaction absorbs energy.
- Heat (kJ) is written on the reactant side.
- Bonds are broken; no new bonds are formed.
- On Table I, the heat of reaction is positive (+).
- The surroundings feel colder because energy is absorbed.
Exothermic Reactions
An exothermic reaction releases energy.
- Heat (kJ) is written on the product side.
- Bonds are formed.
- On Table I, the heat of reaction is negative (−).
- The surroundings feel warmer because energy is released.
Electronegativity
- Electronegativity