What are the possible units of the rate constant, "k" for the given rate equation of a reaction? Rate = k [A][B]
Correct answer: B. mol-1.dm3.s-1
- A. mol.dm-3.s-1
- B. mol-1.dm3.s-1
- C. mol-2.dm3.s-1
- D. mol-1.s-1
Explanation
The units of "k" must be chosen to make the equation dimensionally consistent. Here's the reasoning:- Rate is typically expressed in mol.dm-3.s-1 (moles per liter per second).- [A] and [B] represent concentrations and are in mol.dm-3.To balance the units, "k" must have units of mol-1.dm3.s-1. This allows the units to work out correctly when multiplied by the concentrations of A and B.
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Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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