# General Reaction Rate

1. Jan 20, 2014

### ThatDude

1. The problem statement, all variables and given/known data

This is not a homework question, rather, I am just trying to clarify a concept and example in my textbook.

Ammonia is produced by the reaction of Nitrogen (N2) with hydrogen (H2) as shown in this equation.

N2 + 3 H2 --> 2 NH3

The rate of ammonia production is 5.0 x 10-6 mol/(L * s)

What is the general reaction rate?
What are the corresponding rates for nitrogen and hydrogen transformation?

2. The attempt at a solution

Calculation:

= (1/2) ( 5.0 x 10-6 mol/(L * s) )

= 2.5 x 10-6 mol/(L * s)

My question is: aren't they already giving us a rate when they say that "The rate of ammonia production is 5.0 x 10-6 mol/(L * s)" ... so why is it necessary to use the general reaction rate law to figure out the "rate". Isn't the rate already given. I'm kind of confused about this.

2. Jan 20, 2014

### epenguin

You are not the only one. I have never heard of a "general reaction rate". It should be defined in the same book.

They give a rate of ammonia production in some unspecified circumstances in reasonable units, rate of change of molar concentration per sec. You can easily work out the second part of the question in those same units.

I am not aware either of a "general reaction rate law", at least no useful one.