Studied by 0 people
Looks like no one added any tags here yet for you.
enthalpy change definition
the overall change in energy in a reaction
exothermic definition
a process that releases heat to its surroundings, resulting in a decrease in enthalpy
endothermic definition
a process that absorbs heat from its surroundings, resulting in an increase in enthalpy
what process is it when bonds are broken in the reactants
endothermic
what process is it when bonds are made in the products
exothermic
calorimetry definition
process of measuring how much energy is absorbed or released in a chemical reaction
specific heat capacity definition
how much energy it takes to raise the temperature of a unit mass of a substance by one degree celsius
two examples of exothermic reactions
> combustion of fuels
> respiration
two examples of endothermic reactions
> photosynthesis
> melting ice
calculating rate of reaction
rate of reaction = amount of reactant used in amount of product formed / time taken
factors affecting rate of reaction
> temperature
> catalyst
> concentration
> pressure
> surface area
describe how you would compare the effectiveness of different catalysts on the rate of a reaction
add the same mass of each catalyst to the reactants
time how long it takes for a certain amount of product to be formed, or how long it takes for the reactant to get used up
the catalyst that caused the product to be produced the fastest / reactant used up the fasted is the best catalyst
describe what you can do at the end of a reaction to prove that the solid added acted as a catalyst and not as a reaction
find the mass of the solid before the reaction starts
allow the reaction to finish
filter the products using a funnel and filter paper
dry the remaining solid
find the mass of the dry solid
if the solid had acted as a catalyst the mass should be the same as it was in the beginning of the reaction
how does temperature affect the rate of reactions
as temperature increases, particles have more kinetic energy, causing more successful collisions per unit time, increasing the rate of reaction
how does catalysts affect the rate of reactions
it speeds up the rate of reaction by providing an alternative pathway, with a lower activation energy
how does concentration affect the rate of reactions
as the concentration increases, there are more particles so more successful collisions per unit time so it increases rate of reaction
how does surface area affect the rate of reactions
the reactant is more exposed when it has more surface area so there are more successful collisions per unit time so it increases the rate of reaction
catalyst definition
a substance that speeds up a reaction without being used up
reversible reaction
products of the reaction can react to produce the original reactants
dynamic equilibrium definition
the forward and backward reaction is occurring at the same time are rate
features of a reaction that is in dynamic equilibrium
> the forward and backward reaction occurs simultaneously
> the rate of the forward reaction is equal to the rate of the backward reaction
> the concentration of the reactants remain the same and the concentration of the products remain the same
what happens to the equilibrium if the temperature is increased
the equilibrium shifts to the endothermic side
what happens to the equilibrium if the temperature is decreased
the equilibrium shifts to the exothermic side
what happens to the equilibrium if the pressure is increased
the equilibrium shifts to the side with the least amount of moles / particles
what happens to the equilibrium if the pressure is decreased
the equilibrium shifts to the side with the least amount of moles / particles
what happens to the equilibrium if the concentration is increased
the equilibrium shifts to the other side of the reaction that isnt affected
what happens to the equilibrium if the concentration is decreased
the equilibrium shifts to the side where the concentration was decreased
