chemistry C6-C10 Flashcards
(82 cards)
what does rates of reaction mean
how fast the reactants are bieng used up
formula for rate of reaction
reactants/time taken or products/time take
what does collision theory mean?
for particles to react, they need enough activation energy
4 factors that affect rate of reaction
1)temperature
2)concentration
3)surface area
4)catalyst
what happens when you increase temperature in a reaction
the particles gain energy which allows them to move faster and hence collide more which gives faster rate of reaction
what happens when you increase concentration in a reaction
there’s more particles per unit of volume which allows frequent collisions
what happens when you increase surface area in a reaction
will allow a higher rate of reaction as the increased area means more space for collisions
what does a catalyst mean
speeds up a reaction but isnt used up
what happens if u add a catalyst in a reaction
provides alternative pathway that decreases the activation energy and allows reaction to happen faster
how to calculate mean rate of reaction
divide the products made by seconds
how to calculate mean rate of reaction at a particular time
1)draw tangent until line hits y-axis
2)draw two lines coming off both ends on the opposite end of the line
3)take the y-axis number the line is touching and divide it by the time the other line reached
what does reversible reaction mean
the reaction that can occur backwards and foward
what is le chateliers principle
The principle that if you change the conditions the position of equilibrium shift to counteract the change
what does equilibrium mean
how many reactant to products particles there are
-if more reactants then equilibrium lies to…
-if more products then equilibrium lies to
1)left
2)right
what does hydrocarbons mean
compound that’s formed from carbon and hydrogen
what are simple hydrocarbons? Alkanes or alkenes?
alkanes
list the first four simple hydrocarbons
methane, ethane, propane,butane
CH4,C2H6,C3H8,C4H10
what is the formula for alkanes
C^nH2+2
what is the group of simple hydrocarbons called? what series?
homologous series
what does homologous series mean
group of compounds that have a similar chemical properties
what are the properties of alkanes
boiling points increase as chains increase
-shorter alkanes are more volatile(evaporate easily)
-shorter alkanes are more flammable
complete combustion formula
hydrocarbon+oxygen—-carbon dioxide+water
is combustion exothermic or endothermic
exothermic reaction