Topic 7 Flashcards
(12 cards)
explain how increasing temperature affects the rate of reaction using collision theory
-particles speed up/move faster
-meaning collide more
how does a catalyst speed up reaction
-they decrease activation energy
-they provide an alternative reaction pathway with lower activation energy
-particles can use minimum amount of energy to collide
activation energy
minimum amount of energy they need to react when they collide
how does increasing concentration increase rate of reaction-collison theory
-more concentrated=more particles of reactant in same volume
-particles more crowded
-collide more
how does more surface area increase rate of reaction- collision theory
-increased SA:V
-particles around it have more area to work on
-collide more
precipitation rate of reaction practical
-mix 2 reactants solutions in flask and put it on a paper with a mark on
-meassure how long it takes for mark to disappear looking through the flask
-faster it disappears=faster rate
change in mass(usually gas given off) practical
-put solutions in flask and put flask on mass balance
-as gass released the lost mass is meassured on balance
-quicker reading drops on balance=faster rate
-reaction finished when reading stops changing on balance
the volume of gas given off practical
-flask with gas syringe in
-more gas given off in set time=faster rate
-reaction finished when no more gas produced
-can use results to play a gas volume and tome graph
exothermic reaction profile
like further up-reactants
curver
like far down-products
activation energy=bit between reactants and top of curve
endothermic reaction profile
line far down-reactants
curve
line far up-products
activation energy-between reactants and curve
explain why dissolving ammonium chloride in water is an endothermic process
-temp decreases when it dissolves
-endothermic bc asorbs heat from surroundings
-causing temp of solution to drop
bond energy calculations
overall energy change=energy required to break bonds-energy released by forming bonds
