The strengths of 5.6 volume hydrogen peroxide (of density 1g/ml) in terms of mass percentage and Molarity (M), Respectively are,(take molar mass of hydrogen peroxide as 34g/mol )A     0.85 and 0.25B     0.85 and 0.5C     1.7 and 0.25D     1.7 and 0.5

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

) CalculatetheconcentrationofH2 O2 in FA 3, in mol dm –3 . concentrationofH2 O2 in FA 3 = .............................. mol dm–3 [1](v) When hydrogen peroxide decomposes in the presence of a catalyst, oxygen is produced.H2 O2(aq) H2O(l)+12 O2(g) The ‘volume strength’ of hydrogen peroxide is equal to the volume of oxygen, in dm3 ,produced under room conditions, when 1.00 dm 3 of the solution decomposes.Use your answer to (c)(iv) and the equation above to calculate the volume, in dm3 , ofoxygen produced when 1.00 dm3 of FA 3 decomposes. This is the ‘volume strength’, in vol,of FA 3. (Underroomconditions1.00molofgasoccupiesavolumeof24.0dm3 . If you were unable to calculate the concentration of H2 O2 in FA 3, assume that it is1.02 mol dm –3 . This may not be the correct value.)‘volume strength’ of FA 3 = .............................. vol [2](d) Themaximumerrorinreadinga25.0cm3pipetteis±0.06cm3 . Showbycalculationthatthepipetteismoreaccuratethanaburetteformeasuring25.0cm3 ofsolution................................................................................................................................................................................................................................................................................................... [1] [Total:15]

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

The molarity of 98% by wt. H2SO4 (d = 1.8 g/ml) is

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.