Introduction to Chemistry for Engineers

Introduction to Chemistry

• Chemistry is a branch of physical science that studies the composition, properties, and changes of matter.
• It's sometimes called the central science because it connects physical, life, and applied sciences (like medicine and engineering).
• Chemistry is an empirical science, studied through measurement of physical properties.
• The field of engineering benefits significantly from chemistry.

Intended Learning Outcomes

• Students should be able to explain how chemistry's role connects to engineering.
• Explain the scientific method.
• Understand chemical concepts at different levels (macroscopic, microscopic, and symbolic).
• Describe properties of matter (intrinsic, extrinsic, and measurable).
• Classify matter (mixtures, pure substances, elements, compounds).
• Compare and contrast solid, liquid, and gas states.
• Differentiate between physical and chemical changes of matter.

Accreditation Board for Engineering and Technology (ABET)

• ABET is a professional organization overseeing engineering education.
• ABET defines engineering as the application of mathematical and natural sciences (gained through study, experience, and practice) with judgment to economically use natural materials and forces for humanity's benefit.

Definition of Chemistry

• Chemistry involves the study of matter's composition, properties, and transformation.
• Chemistry is the central science because it connects other fields of study.

Significance of Chemistry

• Chemistry is crucial in engineering design, selection of materials, and understanding electron flow as a foundation for electricity (in electrical engineering).
• Chemistry is essential in the manufacturing process of various products (food, beverages, pharmaceuticals, plastics).
• Chemical advancements and research are crucial for developing new technologies, like drugs and alternative energy sources.
• Chemical knowledge is essential for understanding and creating solutions to environmental issues.

Scientific Method

• Chemistry is a science that utilizes the scientific method.
• The scientific method is a systematic and orderly approach to research to answer questions about the world.
• Steps in the scientific method include observations, hypothesis formulation, constructing experiments, and analyzing results to support or reject the hypothesis.

Models in Science

• Models offer a largely descriptive view of phenomena, like the relationship between gas pressure and temperature.
• Theories offer explanations grounded in more fundamental principles or assumptions about systems.

Matter and Energy

• Matter occupies space and has mass.
• Matter is composed of tiny particles called atoms.
• Mass is a measure of matter, while weight is the gravitational force exerted on an object.

Levels of Understanding/Perspective

• Macroscopic perspective: observing matter, describing properties.
• Microscopic perspective: considering matter's atomic composition and structure.
• Symbolic perspective: using chemical symbols and formulas to represent matter and reactions.

Properties of Matter

• Intrinsic properties are inherent to a substance (e.g., melting point, density, colour).
• Extrinsic properties describe a substance's external qualities (e.g., size, shape, mass, volume).
• Measurable properties are quantifiable, either extensive (dependent on sample size - e.g., mass) or intensive (independent of sample size - e.g., boiling point).
• Physical properties can be observed and measured without altering a substance's identity.
• Chemical properties are observed during chemical changes.

States of Matter

• Solids have a definite shape and volume.
• Liquids have a definite volume but take the shape of their container.
• Gases have neither a definite shape nor volume; they take the shape and occupy the volume of their container.

Classification of Matter

• Matter can be categorized into mixtures (mixtures have variable substance composition) or pure substances (pure substances have a constant composition).
• Pure substances can be further classified into elements and compounds.
• Mixtures can be further divided into a) heterogeneous mixtures (uneven distribution of substances, e.g., sand in water), and b) homogeneous mixtures (evenly distributed substances, e.g., sugar in water).

Pure Substance

• Pure substances contain only one type of matter and have constant composition.
• Pure substances can be elements or compounds; elements are fundamental units, while compounds are combinations of elements.

Element

• Elements are substances composed of only one type of atom.
• Elements are the simplest form of matter.
• 115 known elements exist.
• Elements are represented by chemical symbols

Compounds

• Compounds are substances composed of two or more elements in a definite proportion by mass, forming a molecule.
• Compounds have unique properties different from their constituent elements.
• Compounds are represented by a chemical formula.

Organic Compounds

• Organic compounds contain carbon, and are common in living organisms.
• Examples include hydrocarbons (methane, CH4), sucrose (C12H22O11), and ethanol (CH3CH2OH).

Inorganic Compounds

• Inorganic compounds do not contain carbon.
• Examples include sodium chloride (NaCl), water (H2O), and sulfuric acid (H2SO4).

Mixtures

• Mixtures are combinations of two or more substances that retain their individual properties.
• Mixtures are not represented by a chemical formula.
• Mixtures can be classified into homogeneous (uniform composition, e.g., sugar solution) and heterogeneous mixtures (non-uniform composition, e.g., sand and water).

Changes in Matter

• Physical change alters the form or state of a substance without changing its composition.
• Chemical change alters the structure and composition of a substance. It involves a chemical reaction.
• Chemical changes can release or absorb heat (exothermic/endothermic).

Laws of Conservation

• The Law of Conservation of Mass states matter isn't created nor destroyed in chemical reactions.
• The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed into different forms.

Forms of Energy

• Energy is the capacity to do work.
• Forms of energy include kinetic energy (energy of motion), potential energy (energy of position), radiant energy, thermal energy, chemical energy, and nuclear energy.