Question

the figure below shows student bs results for coarse manganese dioxide lumps. calculate the mean rate of reaction between 30 and 250 seconds for coarse manganese dioxide lumps. use the figure and the equation: mean rate of reaction = volume of oxygen formed / time taken. give your answer to 3 significant figures. volume of oxygen formed time taken

Explanation:

Step1: Read volumes at given times

From the graph, at $t = 30\ s$, volume of oxygen $V_1\approx 70\ cm^3$, at $t = 250\ s$, volume of oxygen $V_2\approx 190\ cm^3$.

Step2: Calculate change in volume and time

Change in volume $\Delta V=V_2 - V_1=190 - 70 = 120\ cm^3$. Change in time $\Delta t=250 - 30=220\ s$.

Step3: Calculate mean rate of reaction

Mean rate of reaction $r=\frac{\Delta V}{\Delta t}=\frac{120}{220}\approx0.545\ cm^3/s$.

Answer:

$0.545\ cm^3/s$