Rate Experiments During a reaction, the?reactants?are used up and changed into the?products This means that as the reaction proceeds, the concentration of the reactants is?decreasing?and the concen...
Activation Energy For a reaction to take place, the reactant particles need to overcome a minimum amount of energy This energy is called the?activation energy (Ea) In?exothermic reactions?the react...
Measuring Rates To measure the?rate of a reaction, we need to be able to measure either how quickly the reactants are used up or how quickly the products are formed The method used for measuring de...
Rate of Reaction Reaction rate Some reactions take place instantly, but most are much slower and it is possible to measure how long these reactions take to reach a certain stage As a chemical react...
Kinetic Theory The?kinetic theory?developed in the 18th?century out of a need to explain how it is that gases exert pressure inside a container Theories about gas particles and movement were extend...
Case study: Ozone & Bond Strength A study of?bond enthalpy?can explain why ozone and oxygen in the atmosphere play very different roles in the flow of energy These processes have a profound eff...
Energy Profiles An energy profile or energy level diagram is a diagram that shows the energies of the reactants, the?transition state(s)?and the products of the reaction with time The?transition st...
Bond Enthalpy Calculations Bond energies are used to find the ΔHr??of a reaction when this cannot be done experimentally The process is a step-by-step summation of the bond enthalpies of the all th...
Bonds & Energy When bonds are broken or made?enthalpy changes?take place A chemical bond is a force of attraction between two atoms Breaking the bond requires the input of energy it is therefor...
Using ?Hf° to Find Enthalpy Changes Standard Enthalpy of Formation is defined as “The enthalpy change when one mole of a compound is formed from its elements under standard conditions” We can use e...
全球高等教育80%以上的優(yōu)質(zhì)資源在歐美國家，而單美國就占了相當(dāng)大一部分，美國有全世界一流的大學(xué)，這也是很多國際生選擇去美國留學(xué)的重要原因。隨著國內(nèi)留美孩子的逐年遞增，很多留學(xué)家庭對于留美的費(fèi)用也非常關(guān)...
Hess's Law using Equations We can use Hess’s Law to solve unknown enthalpy changes by combining equations This requires a methodical step-by-step approach It is necessary to identify how the given ...
