Cambridge AssessmentCANDIDATENAMECENTRECANDIDATENUMBERNUMBERnCHEMISTRY0620142nPaper 4 Theory (Extended)February/March 20231 hour 15 minutesYou must answer on the question paper.No additional materials are needed.INSTRUCTIONS●Answer all questions.Use a black or dark blue pen.You may use an HB pencil for any diagrams or graphs.Write your name,centre number and candidate number in the boxes at the top of the page.Write your answer to each question in the space provided.Do not use an erasable pen or correction fluid.Do not write on any bar codes.You may use a calculator.You should show all your working and use appropriate unitsINFORMATION.The total mark for this paper is 80.The number of marks for each question or part question is shown in brackets ]The Periodic Table is printed in the question paper.This document has 12 pages.IB23030620_42/3RP©UCLES2023[Turn over1 This question is about gases found in clean,dry air and gases found in polluted air.(a)Name one gas found in clean,dry air which contributes to global warming.[1(b)State the percentage of nitrogen in clean,dry air.(c)Name the substance used to remove sulfur dioxide in flue gas desulfurisation.(d)Nitrogen dioxide,NO2,is formed in car engines.Name the equipment in a car exhaust used to remove the NO,fomed in car engines(e)All gases diffuse.(i)Choose from the list of fomulae the gas which diffuses most quickly.Draw a circle around your answer.C02CHNO2Explain your answer to (i).(f)State one adverse effect of carbon monoxide on human health.(g)Carbon dioxide,CO2,is a reactant in photosynthesis.Name the two products of photosynthesis.[2©UCLES20230620/42/F/MW23(h)Complete the dot-and-cross diagram in Fig.1.1 for a molecule of CO2.Show outer shell electrons only.Fig.1.1[Total:11]©UCLES20230620/42/F/MW23[Tum over