SKILLS: Equilibrium and Rates etc. Flashcards

397048750	What are the factors that affect the rate of a chemical reaction?	Temperature, pressure, concentration, use of a catalyst, state of subdivision or particle size, stirring and nature of reactants.
397048751	What is a transition state or activated complex?	The transition state is the point in the reaction where new bonds are forming and the original bonds are breaking. It is the highest PE state for the reaction.
397048752	Does a change in mass alone affect the rate of a chemical reaction?	No.
397048753	What is Ea?	Ea (activation energy) is the minimum energy required for a successfully reactive collision.
397048754	What is an exothermic reaction?	A reaction that converts PE into KE. -Temp. increases. -There is a gain in electron(s). -The energy term in the equation is on the right of the arrow. -The change in H is -ve. -Particles are closer. -Bonds are formed.
397048755	What is enthalpy (H)?	H is stored energy or PE.
397048756	What is an endothermic reaction?	A reaction that converts KE into PE. -Temp. decreases. -Electron(s) are given away -The energy term in the equation is on the left of the arrow. -The change in H is +ve. -Particles are further apart -Bonds are broken
397048757	What does the term 'heat of reaction' mean?	The heat of reaction is the change in PE during a chemical reaction. It has the symbol, (delta)H.
397048758	The Haber Process is used to manufacture ammonia: N2(g) + 3H2(g) <-> 2NH3(g) What reaction conditions should be used to maximise yield?	The forward reaction is exothermic and hence will be favoured by lower temperatures. High pressure favours the reaction as it produces the fewest moles of gas in the system. The removal of NH3 as it is forward, as this will favour the forward reaction.
397048759	A saturated solution of strontium hydroxide containing some undissolved solid was prepared. Would this solution be in a state of equilibrium?	Yes. This is because the two opposing processes are occurring at the same rate. i.e. Some of the undissolved solid particles will be dissolving and some of the undissolved particles will become solid.