Carbon and its Compounds quiz

The number of covalent bonds in a molecule of ethane (C2H6) is:

Which of the following is an unsaturated hydrocarbon?

The functional group present in propanal is:

Which of the following belongs to the same homologous series as CH4?

Butanone is a four-carbon compound with the functional group:

Ethanol reacts with sodium to form:

Vegetable oils are converted into vegetable ghee by:

The substance used to convert ethanol into ethanoic acid is:

Saponification is the reaction in which an ester reacts with:

The heating of ethanol at 443 K with excess concentrated sulphuric acid gives:

Why are carbon compounds generally poor conductors of electricity and have low melting and boiling points? (2 marks)

Why does a saturated hydrocarbon burn with a clean blue flame while an unsaturated one gives a yellow sooty flame? (2 marks)

Draw the structures of cyclohexane and benzene, using C and H symbols, and state the number of carbon atoms in each ring. (2 marks)

Write the names of the following compounds: (i) CH3CH2Br (ii) HCHO (iii) CH3COCH3 (iv) CH3CH2CH2OH. (2 marks)

Why is the conversion of ethanol to ethanoic acid called an oxidation reaction? (2 marks)

What is glacial acetic acid? Why is it so called? (2 marks)

How would you distinguish experimentally between ethanol and ethanoic acid? Give one test. (2 marks)

Why is a mixture of oxygen and ethyne burnt for welding, rather than a mixture of ethyne and air? (2 marks)

What is a substitution reaction? Give one example with a balanced equation. (2 marks)

What change will you observe if you test soap with litmus paper (red and blue)? Explain. (2 marks)

Write the molecular formulae of the first four members of the alkene series, starting from ethene. Calculate the molecular mass of each and show that successive members differ by 14 u. (C = 12, H = 1) (3 marks)

Ethanoic acid reacts with sodium hydrogencarbonate to give sodium ethanoate, water and carbon dioxide. Write the balanced equation and calculate the volume of carbon dioxide evolved at STP when 6 g of ethanoic acid reacts completely. (C = 12, H = 1, O = 16; 1 mole of gas occupies 22.4 L at STP) (3 marks)

Propane is the main component of LPG. Write the balanced equation for its complete combustion and calculate the mass of oxygen needed to burn 44 g of propane completely. (C = 12, H = 1, O = 16) (3 marks)

A hydrocarbon contains 3 carbon atoms. Write the formula and the number of covalent bonds if it is (i) an alkane (ii) an alkene (iii) an alkyne, counting a double bond as two bonds and a triple bond as three. (3 marks)

A student mixes 1 mL of ethanol with 1 mL of glacial ethanoic acid and a few drops of concentrated sulphuric acid and warms the mixture. If 4.6 g of ethanol reacts completely with ethanoic acid, calculate the mass of ester formed and the mass of water produced. (C = 12, H = 1, O = 16) (3 marks)

Read the passage and answer the questions. Carbon forms several allotropes. In diamond, each carbon atom is bonded to four other carbon atoms in a rigid three-dimensional structure. In graphite, each carbon atom is bonded to three other carbon atoms in the same plane, forming hexagonal layers that are held together loosely. Fullerenes are allotropes such as C-60, whose atoms are arranged in the shape of a football. (i) Why is diamond hard while graphite is slippery? (ii) Why is graphite a good conductor of electricity? (iii) Name the scientist after whom fullerene is named and state why it is called so. (5 marks)

Read the passage and answer the questions. Ramesh prepared a solution of soap in soft water and another in hard water in two test tubes. He shook both test tubes vigorously. In one tube, plenty of foam formed, while in the other an insoluble white substance formed and very little foam appeared. (i) In which test tube did foam form readily? Why? (ii) What is the white insoluble substance called, and which ions cause it? (iii) Explain how soap molecules clean oily dirt by forming micelles. (5 marks)

Read the passage and answer the questions. Vegetable oils contain long unsaturated carbon chains, while animal fats generally contain saturated chains. In industry, vegetable oils are heated with hydrogen in the presence of a nickel catalyst to make vanaspati ghee. (i) Name this reaction and write a general equation for it. (ii) What is the role of nickel? (iii) Why are vegetable oils considered healthier than animal fats for cooking? (5 marks)

Read the passage and answer the questions. Ethanol is the active ingredient of all alcoholic drinks and is also used in medicines such as tincture iodine and cough syrups. It is a good solvent. Consumption of small quantities of dilute ethanol causes drunkenness, while intake of methanol, even in small quantities, can cause death. Ethanol is denatured by adding poisonous substances like methanol. (i) Write the chemical formula and IUPAC name of the functional group of ethanol. (ii) Write the equation for the reaction of ethanol with sodium metal. (iii) Why is industrial ethanol denatured, and why is methanol dangerous? (5 marks)

Read the passage and answer the questions. A student was given a set of compounds: CH3OH, C2H5OH, C3H7OH, CH3CHO, CH3COOH and C2H4. (i) Which three of these form a homologous series? What is their general formula? (ii) Identify the aldehyde and the carboxylic acid in the list. (iii) Which compound will decolourise bromine water? Explain why. (5 marks)

Explain covalent bonding with the help of electron dot structures of hydrogen, oxygen, water, methane and ammonia molecules. Why do covalent compounds have low melting and boiling points? Draw the structures clearly. (6 marks)

What are isomers? Draw all possible structural isomers of pentane, C5H12, using C and H symbols. Explain the terms saturated and unsaturated hydrocarbons with examples, and give the structures of ethene and ethyne. (6 marks)

Describe the chemical properties of carbon compounds: combustion, oxidation, addition and substitution reactions. Give one balanced equation for each, and explain why addition reactions are characteristic of unsaturated hydrocarbons. (6 marks)

Describe the properties of ethanoic acid: its reactions with a base, a carbonate and a hydrogen carbonate, and with an alcohol (esterification). Write balanced equations for each, and draw a labelled diagram of the experimental setup for esterification. What is saponification? (6 marks)

What are soaps and detergents? Explain the structure of a soap molecule and draw a labelled diagram of a micelle. Explain why soap does not work well in hard water and how detergents overcome this problem. Mention one environmental concern associated with detergents. (6 marks)