The initial rate of a chemical reaction was measured, and one of the reactants was found to be reacting at a rate of 0.0011 mol/L s . The reaction was allowed to proceed for 15 minutes, and the rate was measured again. What would you predict about the second measured rate relative to the first? The reaction rate would be faster. The reaction rate would be slower. The reaction rate would be the same.

THE REACTION RATE WOULD BE SLOWER

Explanation:

The initial reaction rate of one of the reactants is said to be 0.0011mol/l at the first measurement and after another 15minutes in which the reaction was allowed to go on, the reaction rate in respect to the first will be slower. This is because the reactant is depleted in time, it decreases as time increases and more products are formed, that is product increases. Since no new reactant was said to be added, the reaction rate will slow down as a result of reduced reactant in the system.

Average rate = change in mole of concentration / change in time

Average rate = Δ[A]/Δt = Δ[B]/Δt

Where A is reactant, B is product.

Since the reactant decreases in time, the rate is therefore -Δ[A]/Δt.