528083-question-paper-practical-skills-in-chemistry.pdf -...

This preview shows page 1 - 4 out of 16 pages.

* 7 0 1 2 8 8 8 5 1 4 *INSTRUCTIONSUse black ink. You may use an HB pencil for graphs and diagrams.The practical insert is needed with this paper.Complete the boxes above with your name, centre number and candidate number.• Answerallthe questions.Write your answer to each question in the space provided. If additional space isrequired, use the lined page(s) at the end of this booklet. The question number(s) mustbe clearly shown.• Donotwrite in the barcodes.INFORMATIONThe total mark for this paper is60.The marks for each question are shown in brackets[ ].Quality of extended responses will be assessed in questions marked with an asterisk (*).This document consists of16pages.Turn over© OCR 2018 [601/5371/4]DC (LK/SG) 156071/6Last nameFirst nameCandidatenumberCentrenumberOxford Cambridge and RSAA Level Chemistry B (Salters)H433/03Practical skills in chemistryWednesday 20 June 2018 – MorningTime allowed: 1 hour 30 minutesYou must have:• the Insert (inserted)• the Data Sheet for Chemistry B (Salters)(sent with general stationery)You may use:• a scientific or graphical calculatorOCR is an exempt Charity
2© OCR 2018Answerallthe questions.1A student decides to use a microscale method to synthesise an azo dye and dye a fabric.(a)The student initially makes a small amount of a solution of the diazonium compound shownbelow, starting from an aromatic amine.NN Cl+diazonium compoundName the reagents and conditions needed to make this compound.Reagents...................................................................................................................................................Conditions..............................................................................................................................................[3](b)Naphthalen-2-ol, shown below, is used to make the dye. A piece of cotton is dipped intonaphthalen-2-ol dissolved in sodium hydroxide. The diazonium solution is then added to dyethe cotton red.The coupling reaction involves the carbon atom marked with an asterisk, *.naphthalen-2-olOH*(i)Complete the structure of the azo dye formed in this coupling reaction.OH[1]
3Turn over© OCR 2018(ii)The azo dye formed above has an extended delocalised system.Describe the bonding occurring in a delocalised system and explain why this can lead toorganic compounds being coloured....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................[4](c)Other functional groups can be attached to dye molecules and these can modify the propertiesof the dye.(i)Giveoneproperty of the dye that might be affected if nitro, NO2, groups are attached.......................................................................................................................................[1](ii)Give adifferentproperty affected by the attachment of sulfonate, SO3, groups.

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 16 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
Marklevitz
Tags
Electrochemistry, Standard electrode potential

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture