chemistry

Gas Chromatography - Mass Spectrometry Home > Analytical Chemistry > Gas Chromatography - Mass Spectrometry GAS CHROMATOGRAPHY - MASS SPECTROMETRY What is gas chromatography (GC)? Chromatography using a GC-MS (video) GC-MS Analysis of pharmaceutical drugs in blood samples using Deconvolution Gas Chromatography Detectors Gas Chromatography – Quantitative Analysis     Gas chromatography sample introduction techniques     Headspace Analysis - Gas Chromatography - Analysis of Ethanol in Blood (Forensic Chemistry) How does a mass-spectrometer work? Interpreting Mass Spectra / GC–MS Data Analysis Troubleshooting and maintenance of GC Systems Understanding Columns in Gas Chromatography   Gas chromatography ( GC ) is a separation technique based on the repeated

Properties of Solutions Home > Physical & Theoretical Chemistry > Properties of Solutions PROPERTIES OF SOLUTIONS Dalton’s Law – Law of Partial Pressures Gas Laws – Ideal Gas Law Properties of Solutions - Henry’s Law – Effect of Pressure on Solubility Solutions and Concentration - Solution Composition   Solutions are homogeneous mixtures . Many chemical reactions are carried out in solutions and solutions are closely related to our every day lives. The air we breathe, the liquids we drink and blood and the fluids in our body are all solutions. The components of a solution are: The solvent - the major component of a solution The solute - the minor component of a solution Solutions especially liquid solutions , usually have different properties than either the pure solvent or the solute. For example, pure water freezes a

Thermochemistry Home > Physical & Theoretical Chemistry > Thermochemistry THERMOCHEMISTRY Entropy, Free Energy and Thermodynamic Equilibrium Free Energy, Entropy, Thermodynamic Equilibrium Entropy changes ΔS and Thermodynamic Equilibrium – Solved Examples Phase Changes - Energy Changes - Heating Curves   Thermochemistry is the branch of chemistry concerned with the heat effects that accompany chemical reactions - heat produced by or required for a chemical reaction. In thermochemistry, chemical reactions are divided into two categories: Exothermic (Qreaction < 0) - heat is produced by the reacting system Endothermic (Qreaction > 0) - heat is absorbed by the reacting system Thermochemistry deals with determining quantities of heat produced or absorbed by a reaction both by measurement and by calculation. It rests on Lavo

Chemical Kinetics Home > Physical & Theoretical Chemistry > Chemical Kinetics CHEMICAL KINETICS Rate of chemical reaction - Chemical Kinetics Rates of a chemical reaction and the Collision Model How to determine the order of a reaction by the Initial Rates method   Chemical kinetics is the area of chemistry concerned with the rates (speeds) of reactions . It explains how the rates of different chemical reactions vary over an enormous range of time scales (seconds to years). The main goals of chemical kinetics is to understand the following: The factors that control reaction rates Establish relationships between the rate of a reactions and the amount of reactants present Understand the steps by which a reaction occurs (mechanism of reaction) Optimize conditions to carry out chemical reactions at reasonable rates under proper contro

Lewis Structures - Theory & Examples Home > Physical & Theoretical Chemistry > Physical & Theoretical Chemistry - Lewis Structures - Theory & Examples LEWIS STRUCTURES AND THE OCTET RULE - THEORY & EXAMPLES SO 2 , SO 3 , SO 3 -2 , SO 4 -2 Lewis Structures & the Octet Rule H 2 CO 3 , CO, CO 2 , CO 3 -2 SCN - , OCN - , NCN -2 HCN, CN + , CN - , O 3 COCl 2 , CS 2 , HNCHNH 2 NO, NO 2 , NO 2 + , NO 2 - NO 3 - , HNO 3 , NOCl N 2 O, N 2 O 3 , N 2 O 4 , N 2 O 2 N 2 F + , CF 3 NO, HO 2 NO 2 HClO 3 , HClO 4 , Cl 2 O 4 ClO 2 , ClO 2 + Cr 2 O 7 -2 , CrO 4 -2 , CrO 3 , H 2 CrO 4 PO 4 -3 , PO 3 - , HO 4 P -2 P 2 H 2 , POCl 3 , IO 3 - CH 2 N 2 , CN 2 H 2 , N 2 H 3 + , N 3 - SO 2 Cl, HSO 3 Cl, S 2 O 6 C 2 O 4 -2 , BrO 3 - , N 5 +