chemistry

Buffer Solutions - How to prepare buffer solutions Home > Fundamental Physical Constants - Chemical - Physical - Thermochemical Data > Buffer Solutions - How to prepare buffer solutions Buffer Solutions - How to prepare buffer solutions - Hydrochloric Acid Buffer Buffer solutions play important roles in controlling the solubility of ions in solution and in maintaining the pH in biochemical and physiological processes. Many life processes are sensitive to pH and require regulation withing a small range of H 3 O + and OH - concentrations. Human blood has a pH near 7.4 that is maintained by a combination of carbonate, phosphate, and protein buffer systems. How can we prepare buffer solutions in the laboratory? A buffer solution is any solution that maintains approximately constant pH upon small addditions of acid or base. Adding as little as 0.1 ml of concentrated HCl to a liter of H 2 O shifts the pH from 7.0 to 3.0. T...

Fundamental Physical Constants / Chemical - Physical - Thermochemical Data Home > Chemical News & Interesting / Fundamental Physical Constants / Chemical - Physical - Thermochemical Data CHEMICAL NEWS & INTERESTING / FUNDAMENTAL PHYSICAL CONSTANTS / CHEMICAL - PHYSICAL & THERMOCHEMICAL DATA Fundamental Physical Constants Laboratory Reagents and Solutions Properties of Atoms and Bonds Properties of Molecules Chemistry and Mobile Phones     Hyaluronic Acid chemistry, properties, functions and benefits     Aqueous Equilibrium Constants St Te   The most common fundamental physical constants are presented in these posts. These constants can be categorized as general constants , electron constants , proton constants , neutron constants , atomic constants , matter con...

useful conversion factors between units of Fundamental Physical Constants Home > Fundamental Physical Constants / Chemical - Physical - Thermochemical Data > Fundamental Physical Constants > Useful Conversion Factors between Units of Fundamental Physical Constants Useful Conversion Factors between Units of Fundamental Physical Constants   Certain fundamental physical constants have special importance on account of their universality or place in fundamental theory. A lot of early scientific work was done using the CGS system that has as base units the centimetre, gram and second. The table below lists the more common conversion factors between SI and CGS units.   Table 1: Length CGS unit SI unit Reciprocal   1 inch (in) = 2.54 * 10 -2 m 39.370079   1 foot (ft) = 0.3048 m 3.280839   ...

Fundamental Physical Constants Home > Fundamental Physical Constants - Chemical - Physical - Thermochemical Data > Fundamental Physical Constants Fundamental Physical Constants   Certain physical constants have special importance on account of their universality or place in fundamental theory. These constants are given below in SI units. The figure in brackets is the estimated uncertainty in the last digit.   Table 1: Physical Constants - General Constants Quantity Symbol Value Unit Speed of light in vacuum c 2.997924590(8) * 10 8 m.s -1 Planck constant h 6.62620(5) * 10 -34 J.Hz -1 Electron charge e 1.602192(7) * 10 -19 C Gas constant R 8.31 J.K -1 .mol -1 Gravitational constant G N 6.673 * 10 -11 ...

Electrochemistry - Index Home > Physical & Theoretical Chemistry > Electrochemistry ELECTROCHEMISTRY Balancing Oxidation - Reduction reactions by the Oxidation Number Method Oxidation Numbers: Assigning oxidation numbers to atoms in a chemical compound - Examples Oxidation – Reduction (Redox) Reactions – Balancing Redox Reactions   Electrochemistry is the study of the relationship between electricity and chemical reactions. It is primarily concerned with two processes that involve oxidation-reduction reactions : the generation of an electric current from a chemical reaction and the opposite process, the use of a current to produce chemical change . At the heart of electrochemistry are the oxidation-reduction reactions. These reactions power batteries that in turn are used in cars, calculators, laptops and in our portable electr...