basic concepts questions
1. Predict the molecular formula of an alkane with 13 carbon atoms.
..................................................................................................................................
[Total 1 mark]
2. Bromobutane, CH3CH2CH2CH2Br, can be reacted with hot aqueous sodium hydroxide to prepare butan-1-ol. CH3CH2CH2CH2Br + OH– → CH3CH2CH2CH2OH + Br– A student reacted 8.72 g of bromobutane with an excess of OH–. The student produced 4.28 g of butan-1-ol.
(i) Calculate the amount, in mol, of CH3CH2CH2CH2Br reacted. CH3CH2CH2CH2Br, Mr = 136.9
............................................... mol
[1]
(ii) Calculate the amount, in mol, of CH3CH2CH2CH2OH produced.
............................................... mol
[2]
(iii) Calculate the percentage yield. Quote your answer to three significant figures.
.................................................. %
[1]
[Total 4 marks]
3. But-1-ene is just one isomer with the molecular formula C4H8. Using C4H8 as your example, describe and explain what is meant by structural isomerism and cis-trans isomerism. Include diagrams in your answer. In your answer you should make clear how each type of isomerism is related to structural features. (Allow one lined page).
[Total 7 marks]
4. Cylcohexane and cyclohexene are both cyclic hydrocarbons.
cyclohexane cyclohexene
(i) What is the molecular formula of cyclohexene? .............................................
[1]
(ii) What is the empirical formula of cyclohexene? ..............................................
[1]
(iii) Calculate the percentage, by mass, of carbon in cyclohexene. Give your answer to two significant figures.
answer ...............................................
[2]
[Total 4 marks]
5. Halogenoalkanes are used in the production of pharmaceuticals, polymers and flame retardants.
1-Bromo-2-methylpropane is used in the production of ibuprofen and can be prepared
..................................................................................................................................
[Total 1 mark]
2. Bromobutane, CH3CH2CH2CH2Br, can be reacted with hot aqueous sodium hydroxide to prepare butan-1-ol. CH3CH2CH2CH2Br + OH– → CH3CH2CH2CH2OH + Br– A student reacted 8.72 g of bromobutane with an excess of OH–. The student produced 4.28 g of butan-1-ol.
(i) Calculate the amount, in mol, of CH3CH2CH2CH2Br reacted. CH3CH2CH2CH2Br, Mr = 136.9
............................................... mol
[1]
(ii) Calculate the amount, in mol, of CH3CH2CH2CH2OH produced.
............................................... mol
[2]
(iii) Calculate the percentage yield. Quote your answer to three significant figures.
.................................................. %
[1]
[Total 4 marks]
3. But-1-ene is just one isomer with the molecular formula C4H8. Using C4H8 as your example, describe and explain what is meant by structural isomerism and cis-trans isomerism. Include diagrams in your answer. In your answer you should make clear how each type of isomerism is related to structural features. (Allow one lined page).
[Total 7 marks]
4. Cylcohexane and cyclohexene are both cyclic hydrocarbons.
cyclohexane cyclohexene
(i) What is the molecular formula of cyclohexene? .............................................
[1]
(ii) What is the empirical formula of cyclohexene? ..............................................
[1]
(iii) Calculate the percentage, by mass, of carbon in cyclohexene. Give your answer to two significant figures.
answer ...............................................
[2]
[Total 4 marks]
5. Halogenoalkanes are used in the production of pharmaceuticals, polymers and flame retardants.
1-Bromo-2-methylpropane is used in the production of ibuprofen and can be prepared