rate of reaction graph

[mollykins]

we did an experiment in science, where we looked at the rate of reaction between magnesium and hyrdrochloric acid.

we have to do two graphs, one with gas produced, where i take the average of each strength at each point and plot them, so i have 5 line on the graph. but then i have to do a rate of reaction graph, i think i take the first 20 seconds from each of the lines and divide the amount of gas by 20, to work out how much a second, do i then plot 5 lines, for the different strength in a straight line?

a simple yes will do, if what i explained is correct.

[mollykins]

i know people on here don't like helping with homework, but i just want someone to confirm what i'm doing is right.

[gen2]

Here is a suggestion why you have not had an answer yet.

Unfortunately, it is not possible to follow what you did, or what you are trying to do from your description.

You don't say what you varied, what you measured, how often you took readings, over what period of time?

You mention 5. What is the significance of 5?

Finally a bit of advice, if this is science, NEVER use the term 'amount' - always use more specific terms like 'volume', 'mass', 'length', 'area' etc.

[mollykins]

ok . . .

we reacted mg + hcl and measured the volume of hydrogen produced with a gas seringe.

we changed the concentration of hcl and did 5 different concentrations (nearly said strength then) each concentration we did 5 times and measured the gas every 10 seconds.

on the first graph, we had to plot the amount of gas produced (averages from each point in time of each concentration) against the time, with range bars. so i ended up with a graph with five sloping lines with range bars.

from that information, we have to produce a graph with the rate of reaction on it.

i remember the teacher saying that we have to work out the rate of 1 second for each concentration, so do i divide the total gas by how long it took to get up to its maximum? then draw five straight lines on the second graph? or what?

[mollykins]

aha, i phoned a friend.

he said find the amount of gas produced for each concentration at 20 seconds.

divide that by 20 and get ml/s.

on the second graph have concentration on the x axis and rate on the y.
plot them as either a bar or scatter graph.

[mollykins]

who you say that the higher the concentration of acid, the more the rate of reaction increases, ie from this graph, i can see that the rate of reaction between magnesium and hydrochloric acid increases expotentially with the concentration of the acid.

the rates are as follows (either 0.4 or 0.6 is wrong, because of the shape of the line, i would say it is 0.4)

concentration- molar...........rate - ml/s
0.2......................................0.05 cm /s
0.4......................................0.14
5
cm /s
0.6......................................0.16
5
cm /s
0.8......................................0.27 cm /s
1........................................0.53
5
cm /s
2........................................3.27
5
cm /s