Analytical Chemistry Introduction PDF

ANALYTICAL CHEMISTRY CHEM 1 GLENCY A. PEREZ , MAEd INSTRUCTOR WHAT IS CHEMISTRY? WHY IS THE SCOPE OF CHEMISTRY SO VAST? INTRODUCTION Chemistry is the study of the composition of “matter”, its composition, properties, and the cha...

ANALYTICAL CHEMISTRY CHEM 1 GLENCY A. PEREZ , MAEd INSTRUCTOR WHAT IS CHEMISTRY? WHY IS THE SCOPE OF CHEMISTRY SO VAST? INTRODUCTION Chemistry is the study of the composition of “matter”, its composition, properties, and the changes it  undergoes. WHAT IS WRONG WITH AN ADVERTISEMENT FOR JUICE DRINKS THAT CLAIMS THE JUICE IS ALL-NATURAL AND FREE OF CHEMICALS? Everything is made up of matter; therefore, everything contains chemicals. Even all-natural products are made of chemicals. composition, is What is Chemistry? Chemistry is the study of Chemistry matter, its  processes that matter undergoes, and the energy changes that accompany these processes. Organic Chemistry Inorganic Analytical Chemistry Biochemistry Branches of Chemistry Chemistry Physical Chemistry structures, properties, the Chemistry Organic Chemistry Organic Chemistry is the study of carbon based compounds; with few exceptions like carbon monoxide (CO) and carbon dioxide (CO2) Branches of Chemistry  Chemistry Branches of Chemistry Biochemistry Biochemistry is the study of chemistry of living systems.  Chemistry Branches of Chemistry Physical Chemistry Physical Chemistry is the study of mechanisms, rates,  and energetics of chemical reactions. Chemistry Branches of Chemistry Inorganic Chemistry Inorganic Chemistry, in general is the study of compounds that do  not contain carbon. Chemistry Branches of Chemistry Analytical Chemistry Analytical Chemistry is the study of the quality and quantity of components of substances. SCIENTIFIC METHOD SCIENTIFIC METHOD The scientific method is a process that scientists use to study the world around them. It is a reliable way for scientists to study and gain knowledge. SCIENTIFIC METHOD There are specific steps that should be taken when using the scientific method. 1. MAKE AN OBSERVATION The first thing to do with the scientific method is to come up with a question through observation. Observations are made by using the five senses. 2. MAKE A HYPOTHESIS  Gather information in order to come up with a guess called a hypothesis. Predict the outcome of the problem. 3. EXPERIMENT Once you have a hypothesis, the next step is to design and execute an  experiment to test it. A key to good experiments is to only change one thing, or variable, at a time. VARIABLE -A FACTOR THAT CAN CAUSE A CHANGE IN THE RESULTS OF AN EXPERIMENT INDEPENDENT VARIABLE DEPENDENT THE VARIABLE THAT IS VARIABLE CHANGED TO TEST THE CHANGES ACCORDING TO EFFECT ON THE THE CHANGES OF THE DEPENDENT VARIABLE INDEPENDENT VARIABLE VARIABLE  -A FACTOR THAT CAN CAUSE A CHANGE IN THE RESULTS OF AN EXPERIMENT CONSTANT CONTROL A FACTOR THAT DOES NOT EXPOSED TO THE CHANGE WHEN OTHER INDEPENDENT VARIABLE VARIABLES CHANGE THE STANDARD BY WHICH THE TEST RESULTS CAN BE COMPARED EXPERIMENTAL When experimenting with the growth of a plant, a scientist uses three of the same type of plants, two different fertilizers, equal light, and equal water. What type of variable is the water? a. Dependent b. Independent c. Control d. Interdependent In an experiment designed to determine how the duration of daylight exposure in a 24-hour period affects the flowering of poinsettia plants, the different durations of daylight at which the experimental groups of poinsettia plants are exposed are the _______. a. Controlled variable b. dependent variable c. independent variable d. growth variable RECORD DATA Scientists always record the results of their experiments. Graphs, diagrams, and maps, are ways of recording your data. ANALYZE YOUR DATA  After running all the tests, analyze your data. See if your data matches your hypothesis. PRESENT CONCLUSION The final step in the scientific method is  presenting your conclusion. Discuss your findings and answer your question. CONCLUSION – analyze experimental results to form theories or laws LAW – a concise statement that summarizes results of many observations THEORY – a well tested explanation for a set of observations - Simply a statement of fact that does not try to explain - Tries to explain why but can never be proven ex. Newton’s Law of Gravitation ex. Big Bang Theory Activity No. 1: SCIENTIFIC METHOD Anna’s attention was caught by the sight of a beautiful white flower growing in their yard. She enthusiastically picked three flowers by their stem and placed them in a transparent vase filled with water. Not convinced that a colorless liquid was in the vase, she decided to pour food color into the water. Satisfied, she left the flowers on their own by her window. Late in the afternoon, she returned and found that the flowers turned red! She was amazed and wondered how this happened. Using scientific method or analytical process, help Anna answer her question. ANALYTICAL CHEMISTRY Analytical Chemistry provides the methods and tools needed for insight into our material world. Answering four basic questions about a material sample: What? Where? How much? What arrangement, structure, or  form? ANALYTICAL CHEMISTRY is a branch of Chemistry that deals with characterizing or analyzing the composition of matter, both qualitatively (what is present) and quantitatively (how much is present). BRANCHES OF CHEMISTRY QUANTITATIVE QUALITATIVE is the measurement of the quantities of particular chemical constituents present in a of a particular compound, but not substance (how much). the mass or concentration (what). Chemical tests, flame tests, etc. Several such Gravimetric Analysis and Volumetric tests are widely used in salt analysis Analysis (identification of the cation & anion of determines the presence or absence inorganic salts) Quantitative Analytical Methods Results of Typical Quantitative Analysis comes from two measurements: Mass or volume of the sample  Quantity that is proportional to the amount of analyte (mass, volume, intensity of light, electrical charge) FINAL MEASUREMENT Quantitative Analytical Methods Gravimetric Methods Mass of analyte or mass of compound chemically related to analyte Examples: Cu coated on an electrode Cl precipitated as AgCl  Quantitative Analytical Methods Volumetric Methods Volume of a solution with reagent that reacts completely with the analyte Example: Volume of NaOH that will react with HCl NaOH + HCl → NaCl + H2O Quantitative Analytical Methods Electroanalytical Methods Measurement of electrical properties (potential, current, resistance, and quantity of electrical charge) Quantitative Analytical Methods Spectroscopic Methods Interaction between electromagnetic radiation and analyte Absorption and luminescence spectroscopy Production of radiation by analytes  Emission spectroscopy Quantitative Analytical Methods Miscellaneous Methods Mass to charge ration → mass spectroscopy Rate of reaction → kinetic methods Thermal characteristics → thermal conductivity CHEMICAL ANALYSES SELECTIVE SPECIFIC Analysis that can occur with other substances but exhibits a degree of preference for the substance of interest or the substance of interest or analyte analyte Analysis that can occur only for THE CHEMICAL SYSTEM ANALYTE – specie of special interest MATRIX – part of the sample outside the  analyte Analytical chemistry involves the following methods: The process of separation isolates the required chemical species which is to be analyzed from a mixture.  The identification of the analyte substance is achieved via the method of qualitative analysis. The concentration of the analyte in a given mixture can be determined with the method of quantitative analysis. ANALYTICAL METHODS - Performed either through wet-analysis or instrumental methods WET ANALYSIS – usually employs precipitation, titrimetric, and gravimetric methods  INSTRUMENTAL METHODS – uses sophisticated instruments capable of measuring the analyte’s physical and chemical properties ANALYTICAL METHODS - can either be destructive or non-destructive DESTRUCTIVE ANALYSIS – ends up consuming the sample or renders it unusable for the succeeding analyses; true for all, it not most, wet analyses NON-DESTRUCTIVE ANALYSIS – renders the sample usable for the  succeeding analyses as its composition are kept intact; true for some instrumental analyses ANALYTICAL METHODS - Classified according to the amount of the analyte or constituent present: TRACE– less than 0.01% MINOR– 0.01 to 1.00% MAJOR– beyond 1.00 % ANALYTICAL METHODS  - Classified according to the size of the sample: MACRO– beyond 100 mg (or 100 µL)* SEMI-MICRO– 10 to 100 mg (or 50-100 µL)* MICRO– 1.0 to 100 mg (or