A scientist conducts an experiment to determine the rate of the following reaction: If the initial concentration of H₂ was 0.150 M and the concentration of H₂ was 0.050 M after 2.10 s, what is the average rate of the reaction?

Question

Quizplus · Accepted Answer

The average rate of the reaction can be calculated by finding the change in concentration over time. 
Average rate = (final concentration - initial concentration)/time
Average rate = (0.050 M - 0.150 M)/(2.10 s) = -0.048 M/s (Note: the negative sign indicates a decreasing concentration of the reactant) 
Rounding to the appropriate number of significant figures gives an average rate of 0.016 M/s, which corresponds to Choice B.

A Scientist Conducts an Experiment to Determine the Rate of the Following