Inital Rates Walkthrough

[nadiashaw3K]

Can someone walk me through the method of initial rates when given a table? So confused!!

[Anagh Samavedam 2C]

In the table, find one where two of the values are the same, and the value in question is different, use this value, and the rate value given (on the right side) to calculate the order, (either 0, 1, 2) by the exponent needed. Then do this for the other compounds by isolating one thats the same, and the different compound would have diff values, and repeat to find the order, and then setup the rate equation.

[Averie Moore 2F]

You would choose which rates to compare based on which values in the table are the same and can be used to isolate that compound. You would use that to calculate the order of each component of the reaction and use the overall order to determine the units of your final rate equation.

[anasofia]

If there are 3 molecules of unknown order, A, B, and C, to find the order of A you choose two experiments where [A] changes, but one of the other two concentrations does not (the third variable concentration does not have to be constant for this) you then divide the line of one experiment by the other, it does not matter which divides by which, although whole numbers make things easier, so having the bigger number for A on top might help. The equation will look like Rate 1/Rate 2 =[( A1^x)(B1^y)]/[( A2^x)(B2^y)]. Since B is the concentration that is the same, it cancels, and youre left with the value of R1/R2 = (A1/A2)^x, and solve for x. Once you have that figured out, you repeat this process for two experiments where the [B] does not change, again only one other concentration needs to stay constant, the third can change (because we only go up to overall reaction rate of 3 in this class), and you find the power for the B, once thats found, you can pick two equations where A and B stay constant, but C changes, and then divide them by eachother, and it will end up being R1/R2 = [C1/C2]^z, and solve for z.