Instantaneous rates of reaction

[106046096]

Hi! How is it that the instantaneous rates of each reaction are the negative concentration of the reactant multiplied by 1 over the coefficient of that corresponding reactant and are all equal to one another

[306060519]

Sorry, but there is no such thing as a negative concentration. You might be thinking about the concentration wrong or mistaking it for something else.

[306250289]

that is actually the Unique rate and it has to do with stoichiometrics. The example from lecture used
2NO2 --> 2NO + O2

where NO2 decreases at the same rate that NO increases because they are both 2 moles. However the O2 increases half as fast so thats why it is multiplied by 2 OR the others could be multiplied by 1/2 while O2 is just 1/1

[anasofia]

Hi, the formula of Rate = = -(1/a)*(d[A]/dt) = = -(1/b)*(d/dt) for two reactants A and B. First, the negative sign is because A and B and reactants that are both being [b]consumed so they have a negative rate/decreasing slope. The 1/a or b is because the rate at which A and B are consumed are related by their stoichiometric coefficients, if the formula is 2A + B --> C + D, Rate = = -(1/2)*(d[A]/dt) = = -(1)*(d[B]/dt), because the consumption of B is equal to 1/2 of A, therefore 1/2*A = B. I also was a little confused at first they are not just multiplied by their coefficients, but if you break it down, it would be 2A = B, which is incorrect, because B is half of A, not the other way around. Hope this helps
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[305920501]

I think you're referring to the unique average reaction rate here, in which case it isn't the instantaneous reaction rates of each reaction that are equivalent, but instead it is referring to the average reaction rate of each reactant and each product. The reactants are decreasing over time, so they are negative, and the products are increasing over time, so they are positive. All reactants and products are divided by their stoichiometric coefficient which maintains their relationship to one another in the balanced equation, and an average rate unique to the reaction (the unique average reaction rate) can be used to describe their relationship to one another and not specify the species of each rate.