Rates Of Reaction And Energy Changes Flashcards
What is rate of reaction
How quickly a reaction happens
How do you calculate rate of reaction?
Amount of reactant used or amount of product formed/time
How can you measure reaction rates?
Measure The amount of gas produced using a mass balance the quicker the reading on the balance drops the faster the reaction
Using gas syringe to measure volume of gas given off.the more gas given off in a set time the faster the reaction
Precipitation:mix Two see through solutions add a piece of paper with mark on it.The quicker make goes the faster the reaction.
What happens when you increase the concentration of a reaction?
High concentration of a dissolved reactant increases the amount of particles in the same volume therefore increases the frequency of successful collisions.
What happens when you increase temperature to the reaction?
When temperature increases it increases the rate of reaction because the particles gain energy.Therefore particles move faster and I turn increases the energy and frequency of successful collisions
What does a greater surface area do to rate if reaction?
Increases the rate as more particles of reactant are available and so increases the frequency of successful collisions.
What are catalysts?
Are substances that speed up the reaction by lowering the activation energy without altering the products.They are unchanged chemically in mass at start to the end of a reaction.
Expa,in how a catalysts works?
Provides an alternative reaction path with a lower activation energy
What is an example of a catalyst?
Enzymes
How do you calculate rate of reaction from a graph?
Working out gradient
Change in y/change in x
How do you calculate mean rate of reaction?
Change in mass/chosen time
What is an exothermic reaction?
Is one that gives out energy to the surroundings and the reaction mixture or the surroundings increase in temperature.
What is an endothermic reaction?
One that takes in energy from the surroundings and shown by a fall in temperature of the surroundings
In an endothermic and exothermic reaction are the products at a higher energy level than the reactants or the other way round?
Endothermic reaction-products at higher energy level than reactants
Exothermic reaction-products at a lower energy than the reactants.
What are example of endothermic and endothermic reactions?
Exothermic:
Neutralization
Displacement
Precipitation
Endothermic:
Neutralisation
Precipitation
