Nitrogen Monoxide reacts with hydrogen gas to form nitrogen gas and water (vapor). (i). write a balanced equation for this reaction. (ii). The reaction is experimentally found to be (approx) first-order in H2 and second order in in NO. Write the form if the experimentally-determined rate law and the units of the rate constant (if the concentrations are in molL^-1.
(i) The balanced equation for the reaction can be written as follows:
2NO + 2H2 -> N2 + 2H2O
(ii) Based on the given information, the experimentally-determined rate law can be written as:
rate = k[NO]^2[H2]
In this case, [NO] represents the concentration of nitrogen monoxide in mol/L, and [H2] represents the concentration of hydrogen gas in mol/L.
The units of the rate constant (k) can be determined by observing the units of the rate equation. Since the rate is expressed in mol/(L∙s), and the concentrations are in mol/L, the units of the rate constant will be L/(mol∙s).
(i) The balanced equation for the reaction between Nitrogen Monoxide (NO) and hydrogen gas (H2) to form nitrogen gas (N2) and water vapor (H2O) can be written as follows:
2 NO + 2 H2 -> N2 + 2 H2O
(ii) The experimentally-determined rate law indicates that the reaction is first-order in H2 and second-order in NO. The general form of a rate law is:
rate = k [A]^m [B]^n
where rate is the reaction rate, [A] and [B] are the concentrations of the reactants, k is the rate constant, and m and n are the reaction orders with respect to A and B, respectively.
Since the reaction is first-order in H2, m = 1. Thus, the rate law becomes:
rate = k [H2]^1 [NO]^2
Simplifying, we have:
rate = k [H2] [NO]^2
The units of the rate constant depend on the overall order of the reaction. Since the overall order is the sum of the individual orders (1 + 2 = 3), the units of the rate constant would be (molL^-1)^(3 - 1) s^-1, which simplifies to mol^-2 L^2 s^-1.
if u were not given the experiments values how will u determine the order of reaction?
2NO + 2H2 ==> 2H2O + N2
rate = k[H2][NO]2
You can get the units of k here.
http://en.wikipedia.org/wiki/Reaction_rate_constant#Units