Introduction to Chemistry

• Chemistry studies the substances that compose matter, their properties, how they interact, combine, and change and it uses these transformations to create new substances.
• Chemistry is called the central science because it connects physical sciences with life sciences, pharmaceutical sciences, and applied sciences like medicine and engineering.
• The knowledge of chemicals and chemical processes provides insights into physical and biological phenomena.
• Medicines or pharmaceuticals treat diseases and alleviate pain.
• Chemistry contributes to health care by aiding in the manufacturing and application of surgical materials, and it is used in clinical laboratory tests.
• Chemistry is present in the food we eat, toothpaste, lotions, pharmaceuticals, batteries, and fuels.
• Chemistry studies substances (elements and compounds), while biology studies living things.
• Biochemistry combines chemistry and biology to study substances in living things and their changes within organisms.

Uses of Chemistry

• Everything consists of chemicals, and chemical reactions cause many observable changes.
• Chemistry helps us understand matter's composition, structure, and changes.
• Chemicals are used daily in food, cleaning, and other applications.
• Chemistry applications are visible in industries, transport, food security, agriculture, science, technology, cooking, cleaning, medicine, environmental issues, polymers, and building materials.

Branches of Chemistry

• The main branches of chemistry include organic, inorganic, analytical, physical, and biochemistry.
• Organic chemistry studies compounds containing carbon and hydrogen, including their structure, properties, and preparation.
• Organic chemistry examples include petroleum, medicines, and food.

Organic Chemistry Areas

• Physical organic chemistry studies the interrelationships between structure and reactivity in organic molecules.
• Stereochemistry studies the spatial arrangements of atoms in molecules and their effects on properties.
• Medicinal chemistry involves the design, development, and synthesis of medicinal drugs, overlapping with pharmacology.
• Organometallic chemistry studies chemical compounds with bonds between carbon and a metal.
• Polymer chemistry studies the chemistry of polymers.

Inorganic Chemistry

• Inorganic chemistry studies compounds made of elements other than carbon, also including crystal structures, minerals, metals, catalysts, and most elements that can be found on the periodic table of elements.

Inorganic Chemistry Areas

• Bioinorganic chemistry studies the interaction of metal ions with living tissue, mainly affecting enzyme activity.
• Geochemistry studies chemical composition and changes in rocks, minerals, and the Earth's atmosphere or celestial bodies.
• Nuclear chemistry studies radioactive substances.
• Organometallic chemistry studies chemical compounds containing bonds between carbon and a metal.
• Solid-state chemistry studies the synthesis, structure, and properties of solid materials.

Analytical Chemistry

• Analytical chemistry studies the separation, identification, and quantification of chemical components in materials.
• Qualitative analysis focuses on physical properties and identity, while quantitative analysis measures the amount of substances that are being identified.

Analytical Chemistry Areas

• Forensic chemistry applies chemical principles, techniques, and methods to investigate crime.
• Environmental chemistry studies chemical and biochemical phenomena in the environment, relying heavily on analytical chemistry, including atmospheric, aquatic, and soil chemistry.
• Bioanalytical chemistry examines biological materials like blood, urine, hair, saliva, and sweat to detect specific drugs.

Physical Chemistry

• Physical chemistry uses physics and math to study energy changes in matter and studies the shape of non-living matter and how that affects matter at the visible scale
• Physical chemists study the rate of chemical reactions, the interaction of molecules with radiation, and calculation of structures and properties.

Physical Chemistry Areas

• Photochemistry studies the chemical changes caused by light.
• Surface chemistry studies chemical reactions at substance surfaces, including adsorption, heterogeneous catalysis, colloid formation, corrosion, electrode processes, and chromatography.
• Chemical kinetics studies the rate of chemical reactions, the factors affecting those rates, and reaction mechanisms.
• Quantum chemistry provides a mathematical description of the motion and interaction of subatomic particles, incorporating energy quantization, wave-particle duality, and the uncertainty principle.

Biochemistry

• Biochemistry studies the chemistry in biological processes of all living organisms.
• Biochemical research includes cancer and stem cell biology, infectious disease, and cell membrane and structural biology.

Biochemistry Areas

• Molecular biology studies the interactions between cell systems, such as DNA, RNA, and protein biosynthesis.
• Genetics studies genes, heredity, and variation in living organisms.
• Pharmacology studies mechanisms of drug action and influence of drugs on an organism.
• Toxicology, a sub-branch of Pharmacology, studies the effects of poisons on living organisms.
• Clinical biochemistry studies changes caused by diseases in the chemical composition and biochemical processes of the body.
• Agricultural biochemistry studies the chemistry in plants, animals, and microorganisms.

Matter Classification

• Matter has mass and occupies space.
• Mass measures the quantity of a material; more massive objects require more force to move.
• Matter materials exist as gas, liquid or solid.
• Matter changes via charcoal burning, gasoline burning, grape juice fermentation, or wine souring.
• Matter is categorized into pure substances and mixtures.
• Pure substances can be elements or compounds.
• Mixtures are physically combined structures that can be separated.
• A chemical substance is composed of one type of atom or molecule.
• A substance has a specific composition and properties like sugar and iron.
• Mixtures are physical combinations of two or more substances not chemically joined, like seawater.
• Heterogeneous mixtures have non-uniform composition, like vegetable soup.
• Homogeneous mixtures have uniform composition throughout, in gaseous, liquid, or solid states.
• Elements are substances that cannot be decomposed into simpler substances by chemical changes.

Measurements

• Measurement associates numbers with physical quantities and phenomena and it is fundamental to the sciences, engineering, construction, technical fields, and everyday activities.
• The metric system is the preferred unit system in scientific work.
• SI units (International System of Units) are a set of metric units.
• The scientific method is a logical approach using observation, data collection, measurement, experimentation, and communication.
• Numerical information is quantitative, and nonnumerical information is qualitative.

SI Units and Prefixes

• There are 7 base SI units.
• Metric system uses prefixes to designate multiples and subdivisions of units:

Prefixes for SI Units

• peta- (P) = 10^15
• tera- (T) = 10^12
• giga- (G) = 10^9
• mega- (M) = 10^6
• kilo- (k) = 10^3
• hecto- (h) = 10^2
• deca- (da) = 10^1
• deci- (d) = 10^-1
• centi- (c) = 10^-2
• milli- (m) = 10^-3
• micro- (μ) = 10^-6
• nano- (n) = 10^-9
• pico- (p) = 10^-12
• femto- (f) = 10^-15

Significant Figures

• Significant figures indicate the accuracy and precision of measurements.
• Significant figures are the reliable digits in a number that convey accurate information.

Rules for determining Significant Figures

• All non-zero digits are significant.
• Zeros between non-zero digits are significant.
• Zeros to the right of a decimal point and to the left of the first non-zero digit are not significant.
• Zeros to the right of a decimal point are significant if there is no non-zero digit after them.
• Zeros to the right of the last non-zero digit after a decimal point are significant.
• In a measurement value, zeros to the right of the last non-zero digit are significant.

Rounding Significant Figures

• Omit digits on the right side of the number until the desired number of significant digits is reached.
• If the digit to the right is less than 5, round down.
• If the digit to the right is 5 or greater, round up.

Properties and Physical Quantities

• A physical property is a characteristic of matter not associated with a change in chemical composition, like density, color, hardness, melting/boiling points, and electrical conductivity.
• A chemical change produces matter differing from the matter present before the change, like rust formation or nitroglycerine explosion.
• An extensive property depends on the amount of matter present, such as mass and volume.
• An intensive property does not depend on the amount of matter present, such as temperature.

Temperature Scales

• Fahrenheit, Celsius, and Kelvin are the three temperature scales used today.
• Fahrenheit is based on 32 (freezing point of water) and 212 (boiling point of water).

Conversions

• Celsius to Fahrenheit: TF = (9/5)TC + 32
• Fahrenheit to Celsius: TC = (5/9)(TF - 32)
• Celsius to Kelvin: TK = TC + 273.15
• Kelvin to Celsius: TC = TK - 273.15
• Fahrenheit to Kelvin: TK = (5/9)(TF - 32) + 273.15
• Kelvin to Fahrenheit: TF = (9/5)(TK - 273.15) + 32

Mass and Weight

• Mass measures how much matter an object contains.
• Weight measures the gravitational force on an object, and it depends on mass and location.
• Mass is an inherent characteristic, while weight is a force (Mass * Acceleration).

Volume

• Volume measures the amount of three-dimensional space occupied by matter.
• The cubic meter (m^3) is the SI unit of volume, but liters (L), cubic centimeters (cm^3), fluid ounces (fl oz), pints (pt), quarts (qt), gallons (gal), teaspoons (tsp), and tablespoons (tbs) are used.

Volume Formulas

• Cube: V = l x l x l = l^3
• Cylinder: V = πr^2h
• Sphere: V = (4/3)πr^3 or V = (1/6)πd^3

Density and Specific Gravity

• Density is an intensive property.
• Density determines whether substances float or sink in a liquid.
• Specific gravity is the density of an object divided by the density of water.
• Specific gravity = Density of substance / Density of water (dimensionless).
• The density of water is 1 gram per milliliter, 1 gram per cubic centimeter, or 1000 kg/m^3.

Scientific Notation

• Scientific notation expresses very large or very small numbers.
• It includes a number between 1 and 10 multiplied by a power of 10.

Accuracy, Error, Uncertainty, and Precision

• Scientific measurements include error or uncertainty.
• Precision indicates how well measurements agree with each other.
• Accuracy indicates how well measurements agree with true values.
• Error is the difference between the approximation and the exact value.

Factor-Label Method

• Dimensional Analysis (Factor-Label Method) uses the fact that any number or expression can be multiplied by one without changing its value.

Metric Conversion Charts

• Length and area units conversion metrics are shown below

Metric Conversion Chart for Length

• 1 Centimeter = 10 Millimeters; 1 cm = 10 mm
• 1 Decimeter = 10 Centimeters; 1 dm = 10 cm
• 1 Meter = 100 Centimeters; 1 m = 100 cm
• 1 Kilometer = 1000 Meters; 1 km = 1000 m
• 1 Meter = 10 Decimeter; 1 m = 10 dm
• 1 Foot = 12 Inches; 1 ft = 12 in
• 1 Inch = 2.54 Centimeters; 1 in = 2.54 cm
• 1 Yard = 3 Feet; 1 yd = 3 ft
• 1 Yard = 36 Inches; 1 yd = 36 in
• 1 Mile = 1.61 Kilometers; 1 mile = 1.61 km

METRIC CONVERSION CHART FOR AREA

• 1 square Centimeter = 100 square Millimeters; 1 cm2 = 100 mm2
• 1 square Decimeter = 100 square Centimeters; 1 dm2 = 100 cm2
• 1 square Meter = 10, 000 square Centimeters; 1 m2 = 10, 000 cm2
• 1 square Kilometer = 1 million square Meters; 1 km2 = 1,000, 000 m2
• 1 square Kilometer = 100 hectares; 1 km2 = 100 ha