## Order reaction

Hannah_1G
Posts: 100
Joined: Wed Sep 18, 2019 12:22 am

### Order reaction

How do you tell which order the reaction rate is at? Is it always given? What is it dependent on? I don't very much understand this concept at all, please explain! Thank you!

Kimberly Koo 2I
Posts: 99
Joined: Sat Aug 17, 2019 12:17 am

### Re: Order reaction

The order of a reaction depends on the number of reactants in the reaction. For example, if a reaction has O2 with a coefficient of 2 that are reactants, then the order of the reaction is second order. If a reaction has CO2 with a coefficient of 1 and H2O with a coefficient of 1 in the reactants, then the reaction is also second order. A reaction with a only one H2O in the reactants is first order

Chris Tai 1B
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

### Re: Order reaction

One easy way to determine the order of the reaction is to look at the rate law for the reaction. If there is one reactant, then the order of the reaction will be an order of one. If there are two reactants, then the reaction will be of order two. However, it's also important to look at the coefficients of the reactants before creating the rate law. A good rule of thumb is to add up the exponents for each of the reactants in the rate law = k[A]^a[B]^b[C]^c where k is the rate constant. Once you add up a, b, and c, you'll get the order of the reaction

Daniel Yu 1E
Posts: 100
Joined: Sat Aug 24, 2019 12:15 am

### Re: Order reaction

The order of the reaction can vary depending on the equation and the number of reactants. If you have 3 first order reactants, the order of the reaction is 1+1+1 = 3. If If you have a first order reactant and a second order reactant, the order of the reaction is 1+2 = 3. If you have the rate law, and equation, and the concentrations you can find reaction order.

KnarGeghamyan1B
Posts: 102
Joined: Fri Aug 09, 2019 12:15 am

### Re: Order reaction

You can also look at the units of the k constant if it is given to determine the order.