## Orders

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

Tiffany_Hoang_3C
Posts: 20
Joined: Wed Sep 21, 2016 2:59 pm

### Orders

What does the order (first, second, zero) indicate about a reaction?

Ashley_Thomas_3C
Posts: 20
Joined: Wed Sep 21, 2016 2:56 pm

### Re: Orders

Changing the concentration of substances taking part in a reaction usually changes the rate of the reaction. A rate equation shows this effect mathematically. Orders of reaction are a part of the rate equation (the exponent). If the order of reaction with respect to A is 0 (zero), this means that the concentration of A doesn't affect the rate of reaction. Mathematically, any number raised to the power of zero (x^0) is equal to 1. That means that that particular term disappears from the rate equation. If a reaction rate depends on a single reactant and the value of the exponent is one, then the reaction is said to be first order. A second order reaction is a type of chemical reaction that depends on the concentrations of one second order reactant or on two first order reactants. Thisreaction proceeds at a rate proportional to the square of the concentration of one reactant or the product of the concentrations of two reactants.