Using 10 cm 3of hydrogen peroxide solution gives less accurate results than using 20 cm 3of hydrogen peroxide solution of the same concentration. Explain why.

The rate of reaction is not dependent on the volume of hydrogen peroxide solution. Explain why.

Based on your results, how does increasing the concentration of hydrogen peroxide affect the rate of reaction?

The concentrations of solutions of hydrogen peroxide are often represented in terms of ‘volumestrength’. In this experiment you will determine the ‘volume strength’ of a solution of hydrogen peroxidebytitrationwithacidifiedpotassiummanganate(VII).2MnO 4–(aq)+5H2 O2(aq)+6H+(aq) 2Mn2+ (aq)+8H2O(l)+5O2(g)FA 1 is 0.0300 mol dm –3potassiummanganate(VII), KMnO4 .FA 2isdilutesulfuricacid,H2 SO4 .FA 3isaqueoushydrogenperoxide,H2 O2 .(a) MethodDilution of FA 3● Pipette25.0cm3 of FA 3intothe250cm3 volumetric flask.● Make the solution up to the mark using distilled water.● Shake the flask thoroughly.● Label this diluted solution of hydrogen peroxide FA 4.Titration● Fill the burette with FA 1.● Rinse the pipette thoroughly with distilled water and then with a little FA 4.● Pipette25.0cm3 of FA 4 into a conical flask.● Usethe25cm3 measuring cylinder to add 20 cm3 of FA 2 into the same conical flask.● Perform a rough titration and record your burette readings in the space below.The rough titre is .............................. cm3 .● Carry out as many accurate titrations as you think necessary to obtain consistent results.● Make sure any recorded results show the precision of your practical work.● Record all of your burette readings and the volume of FA 1 added in each accurate titration.Keep FA 1, FA 2 and FA 3 for use in Questions 2 and 3.[7]IIIIIIIVVVIVII39701/33/F/M/20©UCLES 2020 [Turn over(b) From your accurate titration results, obtain a suitable value for the volume of FA 1 to be usedin your calculations.Show clearly how you obtained this value. 25.0cm3 of FA 4required..............................cm3 of FA 1. [1](c) Calculations(i) Give your answers to (ii), (iii), (iv) and (v)totheappropriatenumberofsignificantfigures.[1](ii) Calculate the number of moles of potassium manganate(VII) present in the volumecalculated in (b).moles of KMnO 4 = .............................. mol [1](iii) The equation for the reaction of potassium manganate(VII) with hydrogen peroxide isshown.2MnO 4–(aq)+5H2 O2(aq)+6H+(aq) 2Mn2+ (aq)+8H2O(l)+5O2(g)Use your answer to (c)(ii) to calculate the number of moles of hydrogen peroxide used ineach titration. molesofH2 O2 = .............................. mol HencecalculatetheconcentrationofH2 O2 in FA 4, in mol dm –3 . concentrationofH2 O2 in FA 4 = .............................. mol dm–3

In this experiment some students will be determining how the rate of the reaction depends on the concentration of hydrogen peroxide. Which of the solutions you will be supplied with contain hydrogen peroxide?Question 2Answersolution A1 onlysolution B1 onlysolutions B1 and B2solutions A1 and B1solutions A1 and A2

The equation for the decomposition of hydrogen peroxide is shown.2H_{2}*O_{2}(aq) -> 2H_{2}*O(l) + O_{2}(g) 25.0 cm³ of aqueous hydrogen peroxide forms 48.0 cm³ of oxygen at room temperature and pressure (r.t.p.).Calculate the concentration of aqueous hydrogen peroxide at the start of the experiment using the following steps.Calculate the number of moles of oxygen formed.molDeduce the number of moles of hydrogen peroxide that decomposed.molCalculate the concentration of hydrogen peroxide in mol / d * m ^ 3mol / d * m ^ 3[3]Calculate the volume of O, gas, at room temperature and pressure ( r .t.p.) needed to produce 1260 g of HNO3. Use the following steps.4.The equation for the reaction in stage 3 is shown.4N*O_{2} + 2H_{2}*O + O_{2} -> 4HNO