What is the rate law based on?
The rate law can be determined experimentally using the method of initial rates, where the instantaneous reaction rate is measured immediately on mixing the reactants. The process is repeated over several runs or trials, varying the concentration one reactant at a time.
Which of the following best describes the term rate law?
Which of the following best describes the term rate law? A rate law is a mathematical equation relating reaction rate to the rate constant and to the concentration of one or more reactants. A reaction has a rate law of the form: rate = k[NO]^3[H2].
What are the 5 factors that affect the rate of reaction?
We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the state of subdivision (one large lump versus many small particles) of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst.
How do you write a rate law for an overall reaction?
A The rate law for step 1 is rate = k1[NO2]2; for step 2, it is rate = k2[N2O4][CO]. B If step 1 is slow (and therefore the rate-determining step), then the overall rate law for the reaction will be the same: rate = k1[NO2]2. This is the same as the experimentally determined rate law.
Are catalysts in the rate law?
A catalyst can be present in the rate law if it is a reactant in the rate determining step. Because it is a reactant in that step, it is included in the rate law.
Why does a higher concentration make a reaction faster?
Increasing the concentration of the reactants will increase the frequency of collisions between the two reactants. When collisions occur, they do not always result in a reaction (atoms misaligned or insufficient energy, etc.). Higher concentrations mean more collisions and more opportunities for reaction.
What makes a reaction occur faster?
Usually reactions speed up with increasing temperature (“100C rise doubles rate”). Physical state of reactants. Powders react faster than blocks – greater surface area and since the reaction occurs at the surface we get a faster rate. The presence (and concentration/physical form) of a catalyst (or inhibitor).
What are Mand n in the rate law equation rate k A ][ B?
in which [A] and [B] represent the molar concentrations of reactants, and k is the rate constant, which is specific for a particular reaction at a particular temperature. The exponents m and n are the reaction orders and are typically positive integers, though they can be fractions, negative, or zero.
Why is it important to know the rate law of a chemical reaction?
The rate of a chemical reaction is, perhaps, its most important property because it dictates whether a reaction can occur during a lifetime. Knowing the rate law, an expression relating the rate to the concentrations of reactants, can help a chemist adjust the reaction conditions to get a more suitable rate.