P2 - 6.1 Rates of Reaction Flashcards
The Rate of Extent of Chemical Change
What is meant by the rate of reaction
how fast reactants are turned into products
name a slow example of rate of reaction
rusting copper
name a medium fast example of rate of reaction
magnesium reacting with acid
name a fast example of rate of reaction
fireworks exploding
what 2 things can we look at to determine the rate of reaction
- how fast reactants are used up
- how fast products are formed
if the rate of reaction is fast are products formed slower or faster
faster
if the rate of reaction is slow are products formed slower or faster
slower
what is the rate of reaction equation that includes products
rate of reaction = quantity of products formed/ time taken
what is the rate of reaction equation that includes reactants
rate of reaction = quantity of reactants used/ time taken
what is the quantity of products/reactants measured in
grams
cm^3
moles
dm^3
what is time measured in
seconds
minutes
what is the rate of reaction measured in
grams/s
moles/s
cm^3/s
dm^3/s
What is the rate of reaction if 180cm^3 of hydrogen gas reacts with hydrochloric acid in 2 minutes
Mg + 2HCl -> MgCl2 + H2
Hydrogen gas is a product so we use the equation:
rate of reaction = quantity of products formed/ time taken
convert 2 mins into seconds = 120s
180/120= 1.5cm^3/s
What is the rate of reaction of 3g of magnesium reacting with acid for 4 minutes
Mg + 2HCl -> MgCl2 + H2
magnesium is a reactant so we use the equation:
rate of reaction = quantity of reactant used/time taken
convert 4 mins to seconds = 60x4 = 240s
3/240 = 0.0125g/s
At what time is the rate of reaction is a reaction reacting fastest
at the very beginning
At what time is the rate of reaction is a reaction reacting slowest
at the end
why does the rate of reaction get slower over time
the reactants are being used up so there is a less concentration of atoms to react
what goes along the x axis on a rate of reaction graph
time
what goes along the y axis of a rate of reaction graph
- mass of reactants
or - volume of product formed
in a rate of reaction graph with a y axis of mass of reactant describe what it would look like
-start from the quantity of reactant
- first it will rapidly fall
- ease/slow overtime until it is all used up (at 0g)
in a rate of reaction graph with a y axis of volume of product produced describe what it would look like
- starts at 0 (bottom of graph)
- quickly increase due to lots of hydrogen produced and high concentration of both reactants
- becomes less steep as reaction slows, lower concentration reacting
- becomes a flat line on graph showing reaction has stopped/completed
in a rate of reaction graph with y axis off volume of product why does it quickly increase
lots oof hydrogen produced in a high concentration of both reactants
What is the rate of reaction if 0.6moles of magnesium reacts with hydrochloric acid in 2 minutes
(answer must be in minutes)
magnesium is a reactant
rate of reaction = quantity of reactant used/ time taken
rate of reaction is being measured in mol/min
0.6/2 = 0.3mol/min
which is a larger unit? cm^3 or dm^3
1 cm^3 = 1000 dm^3
cm^3
how do you convert from dm^3 into cm^3
x1000
how do you convert from cm^3 into dm^3
/1000
what is 5000cm^3 in dm^3
cm^3 -> dm^3 = /1000
5000/1000 = 5dm^3
what is 50dm^3 in cm^3
dm^3 -> cm^3 = x1000
50x1000= 50000cm^3
When you strike a match it causes a tiny amount of red phosphorus to be converted to white phosphorus, which can then ignite spontaneously in air. Is this reaction slow or fast
fast
0.4g of magnesium reacts completely with dilute hydrochloric acid in 1 min 20s. What is the overall rate of reaction? give your answer in g/s
magnesium is a reactant
rate of reaction = quantity of reactant used/ time taken
1min 20s = 60+20=80s
0.4/80 = 0.005g/s
Mg + 2HCl -> MgCl2 + H2
90cm^3 of hydrogen gas was produced after 5 mins. What is the overall rate of reaction? give your answer in cm^3/s
hydrogen gas is a product
rate of reaction = quantity of product formed/time taken
5 mins = 60x5= 300s
90/300 = 0.3cm^3/s
