learning log
chapter 17 chemical kenetics
Chemical Kenetics is a branch of chemistry that studies the the reaction rates of chemical reactions. the rate of reactions can only be proved through experiment and the data is used to slove constants. Reaction mechanism are the steps reactions take to form into products and are shown in a step by step process. Those substances that are preasent in the mechanism but not in the overall reaction are called intermeadiates. The normal equation is then called the net eqauation. There are three things molecules need to start a reaction. These include collision, correct orientation, and sufficent kenetic energy. An equation can be represented as graph. In a the graph the series of the reaction will take place in a curve and then go down for the products. There will always be a curve when dealing this king of graph with the reactions energy over time weither that reaction be exothermic or endothermic. The peak or the curve in a reaction is the activation complex when the reaction as a whole has the most energy. The amount of energy absorbed from the reactants to the activation energy is the activation energy represented by Ea. The energy from the produts to the activation energy is the reverce activation energy and is show by Ea' the apostrophe meaning prime. The change from the reactants to the products is the change in energy shown as delta E. There are five things that can determine reaction rate. These include the nature of the reactants determined by the electron configuation, surface area, temperature, consentration, and catalysts. A catalysts are substances that lower the activation energy by assisting the orientation of molecules. One can measure the rate of a reaction is change of consentration divided by change in time. The rate law is R=k[A]^n[B]^m where R is the reaction rate, A and B are the reactants consentration, n and m are the reaction orders, and k is the constant. n and m can only be determined via experimentation. To solve for n and m one of the reactants need to be constant and solve for the other reactants exponent. Once n and m are solved one can solve for the constant by picking one experiment and using the consentration and rate including the exponents. Then solve for k.
lab abstract
This week in lab a comparison was made between different factors effects reaction rate the most out of consentration, temperature, surface area, and a control. The control had 1.0 M consetration with a 2 cm room temperature in two centimeter strips. Of the variables tested a decrease in consentration layed the biggest fact when determining rate of reactions increasing the time many times over. The quickest substance was surface area nearly equal to temperature. Overall the data between groups was contradictory for a whole decision.