Chemistry Chemistry is a physical science. Chemistry is the study of composition, structure, and properties of matter, the process that matter undergoes and the energy changes that accompany these process. Chemical- A chemical any substance that has a definite composition.
Chemistry Scope of chemistry- Chemistry has a wide range of studies including: Materials Energy (conversion, production, storage) Medicines & Biotechnology Agriculture ( fertilizers, pesticides) The environments (identification of pollutants, and their preventions, global warming, acid rain etc.) The universe ( materials from moon or mars, search for water and life )
Branches of chemistry Organic chemistry- Study of carbon containing compounds. Inorganic chemistry-the study of non organic substances. Physical chemistry- The study of properties and the changes of matter and their relation to energy. Analytical chemistry- The identification of the components and composition of material Biochemistry- the study of substances and the processes occurring in living things. Theoretical chemistry- The use of mathematics and computer to understand the principles behind observed chemical behavior and to design and predict the properties of new substance.
Matter- Any thing which has mass and occupies volume is called matter Matter (mass & Volume) Can it be separated Yes No Mixture (impure) Substance (pure) Is it a single Phase? Can it decompose in lab? Yes No Yes No Homogeneous Heterogeneous Compound Element Mixture Mixture Air, wine, steel, gasoline Soil, pizza, salsa sugar, water, wax Gold, hydrogen, carbon
Mixture- A blend of two or more kind of matter Mixtures can be separated by using physical methods Use of magnet ( iron pieces, etc) Filtration - Insoluble substance can be retained on filter paper. Decantation- Suspended (insoluble) particles will settle down. Evaporation- Solvent will evaporate, and nonvolatile solid is left behind. Distillation- A volatile solvent is heat in a flask, vapors are cooled with a condenser and collected in a container. Chromatography- Different compounds move with different speeds through a moving medium.
Scientific Method- A logical approach to solve problems by observing and collecting data, formulating hypothesis, testing hypothesis, and formulating theory supported by more data. Observing and collecting data. Collect information from the experiment System- It is a specific portion of matter in a region of space that has been selected for study during an experiment. Forming Hypothesis-Testable statement is called Hypothesis. Testing hypothesis- It requires experimentation to prove or disprove hypothesis. Experiment with controlled, independent and dependent variable. Model- It is more than a physical object; It explains how does a phenomenon occur and how data or event are related. Theorizing- A broad generalization statement that explains a body of facts.
SI Units of measurement Quantity = 5lb apples, 2meter rope, 5 kilogram sugar Quantity = # followed by a unit to indicate the quantity. Mass (m) - Quantity of matter – Unit is kilogram - kg Length (l) – quantity is length - unit meter – m Time (t) – Quantity is time – unit is second – s Temperature (T)- degree of hotness (or coldness) – unit Kelvin- K
Derived units- combination of two or more base units Area (A) = length (cm) x width (cm) = ……… cm2 Volume (V) = length cm x width cm x height cm = …… cm3 Density = mass g/ volume ml = ……. g/ml or g/cm cube Concentration( C) = moles/liter Specific heat (cp) = j/g