Answer to Question #265776 in Physical Chemistry for priya

Question

A recently graduated chemistry student got employed as a secondary school teacher. His task was to design some interesting experiments that involved computing, maths and chemistry to be displayed at the open day to attract more students to choose science.

His experiments involved mixing some chemicals and observing the colour change. He noticed that if one of the reactant's volume was varied, the time taken for colour of the solution to change also varied. So he obtained the results and tabulated them.  Using these data, explain what important information can be calculated. 

Time for the colour to change: 1m20s, 1m10s, 50s, 45s, 35s, 30s, 25s, 22s

Volume of reactant: 1, 2, 3, 4, 5, 6, 7, 8

Answer 1

A measure of the rate of the reaction at any point is found by measuring the slope of the graph. The steeper the slope, the faster the rate. Because the initial rate is important, the slope at the beginning is used.

In the second graph, an enlarged image of the very beginning of the first curve, the curve is approximately straight. This is only a reasonable approximation when considering an early stage in the reaction. As the reaction progresses, the curvature of the graph increases. The slope of this linear region is V/t.

Suppose the experiment is repeated with a different (lower) concentration of the reagent. Again, the time it takes for the same volume of gas to evolve is measured, and the initial stage of the reaction