The rate and extent of chemical change Flashcards
what does the slope of the mass of products look like
an upwards curve
what does the slope of the mass of reactants look like?
a downwards curve
how do you find the rate of reaction at a specific point?
draw a tangent on the curve then find the gradient
what does increasing the surface area do to the rate of reaction?
increases it
why does a higher surface area increase the rate of reaction?
there is a higher frequency of collisions
why does increased temp increase the rate of reaction?
the particles move quicker with more energy so more reactions happen
is a catalyst used up in a chemical reaction?
no
what changes the rate of a reaction
a catalyst
what does a catalyst decrease?
activation energy
how does a catalyst speed up the reaction
providing a different path for the reaction to happen, lowering the activation energy
what does reversible mean?
to change something back to a previous state
how does a reversible reaction work
where the products can react to form the reactants again
what happens if a reversible reaction is endothermic in one direction?
it is exothermic in the other
what is a closed system?
a system where no reactants or products can enter
when is equilibrium reached in a reaction
when the forwards and backwards reactions occur at the same rate
what is Le chateliers principle?
when a change is made to the conditions then the system responds to counteract the change
what is the structure for writing a answer to if the concentration is changed?
what equilibrium does to counteract the change, how it does this, forwards or backwards, left or right
what is the structure for writing a answer for if the temp is changed?
what does the equilibrium do, endo or exo, forwards or backwards, left or right, yield increase or decrease
what is the structure for writing a answer if the pressure is changed?
what does the equilibrium do, does it favour the one with more or less gas molecules, forwards or backwards, left or right, yield increase or decrease
if there is the same gas molecules on each side does anything change?
no
what is the minimum energy for a successful collision called?
activation
what 4 factors affect rate of a reaction?
temperature, concentration, surface area, pressure
what kind of reaction does the equilibrium favour if the temperature is increased?
endothermic
what kind of reaction does the equilibrium favour if the temperature is decreased?
exothermic
