00:01
Remember that the rate of a reaction is always positive.
00:06
So to calculate the rate of reaction between time 0 and 10 seconds, we can look at the change in the concentration of the reactant per unit time, but because that concentration is decreasing, we need to multiply by negative 1 over the coefficient, the coefficient being 1, and this will be equal to the rate of the reaction.
00:29
The change in concentration of the reactant is the 5.
00:32
Final concentration minus the initial concentration, the concentration at time at 10 seconds, minus the concentration at 0 seconds, divided by 10 seconds minus 0 seconds, gives us 0 .0087 molar per second a positive value.
00:49
We'll do the same thing between 50 and 40 seconds, concentration at 50 seconds minus concentration at 40 seconds divided by 50 seconds minus 40 seconds.
01:02
This gives us a negative number, so we have this negative to give us a positive rate...
