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Transcription of this question: 4.This question is about the decomposition of hydrogen peroxide.(a)(b)Suggest why many chemicals, including hydrogen peroxide, are kept in brown bottlesinstead of clear colourless bottles.Hydrogen peroxide decomposes to water and oxygen when a catalyst such aspotassium iodide, KI, is added.KI (aq)2H202 (aq) 02 (g) + 2H20 (l)In a laboratory experiment solutions of potassium iodide and hydrogen peroxidewere mixed and the volume of oxygen generated was recorded. The volume wasadjusted to O at t = O.o5 10 15 20 25The data for the first trial is given below.Time I s100700Volume of 02 (g) I cm32.56.511.015.0Plot a graph on the axes below and from it determine the average rate offormation of oxygen gas in cm3 02 (g) s15141312111070 100 200 300 400 500 600 700Time / sAverage rate of reaction:(ii )Two more trials (2 and 3) were carried out. The results are given below.Trials23Volume of0.20 mol dm-3KI (aq) I cm310.010.020.0Volume ofdeionisedwater I cm315.010.05.0Volume of 3 %H202 (aq)I cm35.010.05.0Average rate ofreactionI cm’ 02(g) s-‘0.04290.0451Determine the rate equation for the reaction and its overall order, using youranswer from (b)(i).Rate equation:Overall order:(ii i)Additional experiments were carried out at an elevated temperature. On the axesbelow, sketch Maxwell—Boltzmann energy distribution curves at two temperaturesTl and L, where T,..2Kinetic energy(v)Apart from a greater frequency of collisions, explain, by annotating your graphs in(b)(iii), why an increased temperature causes the rate of reaction to increase.Mn02 is another possible catalyst for the reaction. State the IUPAC name for Mn02.(c)Comment on why peracetic acid, CH3COOOH, is always sold in solution with ethanoicacid and hydrogen peroxide.H202 (aq) + CH3COOH (aq) CH3COOOH (aq) + H20 (l)(d)Sodium percarbonate, 2Na2C03•3H202, is an adduct of sodium carbonate andhydrogen peroxide and is used as a cleaning agent.Mr (2Na2COa.3H202) = 314.04Calculate the percentage by mass of hydrogen peroxide in sodium percarbonate,giving your answer to two decimal places.

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