first order of rxns

[Mary Grace Stevens 3G]

If a reaction is considered first order, does that mean that n is always 1 in first order reactions?

[Lisa Seidl 3H]

I am pretty sure the value of n will vary, but this also confused me in the lecture on monday since I am pretty sure t=0 and ln[a]o=c but I am not sure if there is a set value for n.

[clairehathaway 2J]

In class we learned that the generic form of a Differential rate Law is Rate = k[R]^n. I'm pretty sure that for first-order reactions the n in that equation will always be 1.

[Karl Yost 1L]

Yes, I believe so. Since the exponent in the rate law R=k[A]^n is always the reaction order, n=1. However, for second order reactions, it's important to remember that the overall order of the reaction is the sum of the orders w/ respect to the different reactants involved in the rate determining step (long step). As a result, if we have the reactants A and B, we can have the following combinations for a second order rate law:

1) R=k[A][B]
2) R= k[A]^2
3) R=k[B]^2

[Anna Yang 1A]

If it is first order, its n value will be 1. If zero or second, n will be 0 or 2 respectively.

[Anna Yang 1A]

However, for overall order of the reaction, you would add up the n, m, l values so a reaction with two first orders would have an overall order of 2.

[Lucy_Balish_3G]

Yes, that is the definition of a first oder reaction because the n value has to be one or else it is not first order.

[Neal_Agarwal_3B]

For a reaction to be considered first order the sum of all the orders have to equal 1. It is possible that some reactants may be zero order and others be first order as together that would still total to 1. Its important to look at the orders of all the reactants to find the overall reaction order.

[LarisaAssadourian2K]

That's correct. N is always 1 for first order reactions. In addition, it would be 2 for second order and 0 for a zero order.

[Olivia Smith 2E]

Yes for zero order n=0, for first n=1, and for second n=2

[Stephen Min 1I]

Yes, that is correct and if there were more than one starting chemicals the overall order must still pertain to only one.

[Maya Johnson 2a]

Yes, n=1 for first order, and 0 and 2 for zero and second order.

[Brandon Le 3C]

When the reaction is in first order, the value n will always be 1. When the reaction is in zero or second order, the value for n would be 0 and 2, respectively.

[Gigi Elizarraras 2C]

Yes:) I would assume that n=1 for first order reactions, and similarly n=0 for zero order
hope this helps:)

[sophia kosturos 2B]

yes, that's correct. You can observe that a reaction is first order if n=1 and vice-versa, if n=1 you can determine that the reaction is at first-order. If n=0 or n=2, this means that the reaction is either zero-order or second-order, respectively.