Calculate the rate of chemical reactions by measuring the rate of formation of products or the depletion of reactants. (Formula: rate of reaction = increase in product concentration (∆[P]) time taken or decrease in reactant concentration (−∆[R]) time taken)

In an experiment, the concentration of a reactant decreases from $0.80 \text{ mol/dm}^3$ to $0.32 \text{ mol/dm}^3$ in $8.0$ minutes. Which option correctly states the average rate of reaction?

A student conducts an experiment to measure the rate of the reaction: $$2\text{H}_2\text{O}_2(aq) \rightarrow 2\text{H}_2\text{O}(l) + \text{O}_2(g)$$ Refer to the concentration–time graph below. What is the average rate of formation of oxygen gas between $t = 0$ s and $t = 60$ s?

A student investigates the decomposition of hydrogen peroxide (\( \text{H}_2\text{O}_2 \)) in the presence of a catalyst: \( 2\text{H}_2\text{O}_2(aq) \rightarrow 2\text{H}_2\text{O}(l) + \text{O}_2(g) \). The concentration of hydrogen peroxide was measured at different times during the reaction. Initial concentration of \( \text{H}_2\text{O}_2 \) = \( 0.800 \) mol L\(^{-1}\) Concentration of \( \text{H}_2\text{O}_2 \) after \( 240 \) seconds = \( 0.320 \) mol L\(^{-1}\) Calculate the average rate of reaction in terms of the depletion of \( \text{H}_2\text{O}_2 \) over the \( 240 \) second time interval. Express your answer in mol L\(^{-1}\) s\(^{-1}\) to three significant figures. Show your working.

In a laboratory experiment, the decomposition of hydrogen peroxide is monitored. The concentration of hydrogen peroxide decreases from $2.40 \text{ mol/dm}^3$ to $1.80 \text{ mol/dm}^3$ over a period of 120 seconds. (a) Calculate the change in concentration of hydrogen peroxide. (1) (b) Calculate the average rate of reaction, correct to 2 significant figures. (1)