Explain the mechanism of the cleansing action of soaps.
[question] Question. Explain the mechanism of the cleansing action of soaps. [/question] [solution] solution: A molecule of soap has two dissimilar ends. At one end is the hydrocarbon chain, which is water repellent and the other end is carboxylate anion which is polar end. When soap is dissolved in water, many molecules come together and form a group called micelle. These micelles are formed because their hydrocarbon chains come together and the polar ends are projected outward. When a cloth wi...
Give a test that can be used to differentiate between
[question] Question. Give a test that can be used to differentiate between butter and cooking oil. [/question] [solution] solution: As cooking oil contains unsaturated hydrocarbons it will undergo addition reaction whereas butter contains saturated hydrocarbons so it will not give addition reaction (hydrogenation) thus hydrogenation reaction can be used. [/solution]...
Which of the following hydrocarbons undergo addition reactions ?
[question] Question. Which of the following hydrocarbons undergo addition reactions ? $\mathrm{C}_{2} \mathrm{H}_{6}, \mathrm{C}_{3} \mathrm{H}_{8}, \mathrm{C}_{3} \mathrm{H}_{6}, \mathrm{C}_{2} \mathrm{H}_{2}$ and $\mathrm{CH}_{4}$ [/question] [solution] solution: $\mathrm{C}_{3} \mathrm{H}_{6}$ and $\mathrm{C}_{2} \mathrm{H}_{2}$ because they are unsaturated hydrocarbons compounds. [/solution]...
What is hydrogenation ?
[question] Question. What is hydrogenation ? What is its industrial application ? [/question] [solution] solution: Unsaturated hydrocarbons add hydrogen in the presence of palladium or nickel. This reaction is called hydrogenation. This reaction is industrially used in the conversion of vegetable oils into vegetable ghee. [/solution]...
What change will you observe if you test
[question] Question. What change will you observe if you test soap with litmus paper (red and blue)? [/question] [solution] solution: Soap is alkaline in nature therefore turns red litmus blue and no effect on blue litmus. [/solution]...
Explain the formation of scum
[question] Question. Explain the formation of scum when hard water is treated with soap. [/question] [solution] solution: Hard water contains calcium and magnesium ions. When soap comes in contact with hard water, these ions form calcium and magnesium salts of fatty acids which are insoluble in water. These calcium or magnesium salts precipitate out in the form of scum. [/solution]...
Why are carbon and its compounds used
[question] Question. Why are carbon and its compounds used as fuels for most applications? [/question] [solution] solution: When carbon is heated in presence of excess of air or oxygen, it forms carbon dioxide. During its formation, a large amount of heat and light are released. Further, once ignited, carbon and its compoundskeep on burning without needing additional heat energy. [/solution]...
Why does micelle formation take place when soap is added to water?
[question] Question. Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents like ethanol also? [solution] solution: A molecule of soap has two dissimilar ends. At one end is the hydrocarbon chain which is water repellent. At the other end carboxylate anion is present which is water soluble end. When soap is dissolved in water, many molecules come together and form a group called micelle, these micelles are formed because their hydrocarbon ch...
How can ethanol and ethanoic acid be differentiated
[question] Question. How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties? [/question] [solution] solution: [/solution]...
What is an homologous series?
[question] Question. What is an homologous series? Explain with an example [/question] [solution] solution: A family of organic compounds having the same functional group, similar chemical properties and the successive members of which differ by a $\mathrm{CH}_{2}$ group or 14 mass units. e.g. $\mathrm{CH}_{3} \mathrm{OH}$ (methanol) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}$ (ethanol) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}$ (propanol) They constitute homologous series o...
Draw the electron dot structure of
[question] Question. Draw the electron dot structure of (a) Ethanoic acid (b) $\mathrm{H}_{2} \mathrm{~S}$ (Hydrogen sulphide) (c) Propanone (d) $\mathrm{F}_{2}$ (Fluorine) [solution] solution: (a) Ethanoic acid (b) $\mathrm{H}_{2} \mathrm{~S}$ (Hydrogen sulphide) (c) Propanone (d) $\mathrm{F}_{2}$ (Fluorine) [/solution]...
Explain the nature of the covalent
[question] Question. Explain the nature of the covalent bond using the bond formation in $\mathrm{CH}_{3} \mathrm{Cl}$. [/question] [solution] solution: Atomic number of C, H & Cl are 6, 1 & 17 respectively. Their electronic configurations are Carbon – 2, 4 Hydrogen – 1 Chlorine– 2, 8, 7 As C need 4 electrons to complete its octet, H needs 1 electron to complete its duplet and Cl needs 1 electron to complete its octet. So, $\mathrm{C}$ share its 4 electron, one electron each with $3 \mathrm{H}$ ...
While cooking,
[question] Question. While cooking, if the bottom of the vessel is getting blackened on the outside, it means that (1) the food is not cooked completely (2) the fuel is not burning completely (3) the fuel is wet (4) the fuel is burning completely [/question] [solution] solution: (2) the fuel is not burning completely [/solution]...
Butanone is a four-carbon compound
[question] Question. Butanone is a four-carbon compound with the functional group, (1) Carboxylic acid (2) aldehyde (3) ketone (4) alcohol [/question] [solution] solution: (3) ketone [/solution]...
Ethane, with the molecula
[question] Question. Ethane, with the molecular formula $\mathrm{C}_{2} \mathrm{H}_{6}$ has (1) 6 covalent bonds (2) 7 covalent bonds (3) 8 covalent bonds (4) 9 covalent bonds [/question] [solution] solution: (2) 7 covalent bonds [/solution]...
Would you be able to check if water is hard by
[question] Question. Would you be able to check if water is hard by using a detergents ? [/question] [solution] solution: No, because no scum formation takes place when detergent is added to hard water. [/solution]...
What are oxidising agents?
[question] Question. What are oxidising agents? [/question] [solution] solution: Oxidising agents are substances which are capable of adding oxygen to other substances, for examples, both alkaline potassium permanganate and acidified potassium dichromate can convert ethanol to ethanoic acid. e.g. alkaline potassium permanganate $\mathrm{KMnO}_{4}$, acidified potassium dichromate $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$. [/solution]...
How would you distinguish experimentally
[question] Question. How would you distinguish experimentally between an alcohol and a carboxylic acid? [/question] [solution] solution: Sodium bicarbonate test Take a small amount of each compound in a test tube and add to it an aqueous solution of $\mathrm{NaHCO}_{3}$. The compound which produces brisk effervescence due to the evolution of $\mathrm{CO}_{2}$ must be a carboxylic acid [/solution]...
A mixture of oxygen and ethyne is burnt for welding.
[question] Question. A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used? [/question] [solution] solution: Ethyne is an unsaturated hydrocarbon, therefore, combustion of ethane in air produces a yellow flame with black smoke due to the presence of unburnt carbon in it. Due to this incomplete combustion heat produced is also low and a high temperature usually needed for welding cannot be attained. That is why mixture of ethyne & oxygen is ...
Why is the conversion of ethanol to ethanoic
[question] Question. Why is the conversion of ethanol to ethanoic acid an oxidation reaction? [/question] [solution] solution: The reaction showing the conversion of ethanol to ethanoic acid can be shown as : A molecule of ethanol contains one oxygen alone while that of ethanoic acid contains two oxygen atoms. Since oxidation involves addition of oxygen therefore, conversion of ethanol to ethanoic acid is an oxidation reaction. Alternatively, a molecule of ethanol contains six hydrogen atoms whi...
How would you name the following compounds?
[question] Question. How would you name the following compounds? (i) $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{Br}$ [/question] [solution] solution: (i) Bromoethane (ii) Methanal (iii) Hexyne [/solution]...
Draw the possible structural isomers
[question] Question. Draw the possible structural isomers for bromopentane. [/question] [solution] solution: (i) Bromopentane $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{Br}$ [/solution]...
Draw the structure for the following
[question] Question. Draw the structure for the following compounds : (i) Ethanoic acid (ii) Bromopentane (iii) Butanone (iv) Hexanal [/question] [solution] solution: (i) Ethanoic acid $\longrightarrow \mathrm{CH}_{3} \mathrm{COOH}$ (ii) Bromopentane $\longrightarrow \mathrm{C}_{5} \mathrm{H}_{11} \mathrm{Br}$ (iii) Butanone $\longrightarrow \mathrm{CH}_{3} \mathrm{COC}_{2} \mathrm{H}_{5}$ <img src="/media/uploads/2021/12/Draw-the-structure-for-the-following-compounds-03.png" alt="Draw the struc...
What will be the formula and electron
[question] Question. What will be the formula and electron dot structure of cyclopentane? [/question] [solution] solution: Cyclopentane $\mathrm{C}_{5} \mathrm{H}_{10}$ Electron dot structure [/solution]...
What are the two properties of carbon which led
[question] Question. What are the two properties of carbon which led to the huge number of carbon compounds we see around us? [/question] [solution] solution: (i) Catenation (ii) Tetravalency [/solution]...
How many structural isomers
[question] Question. How many structural isomers can you draw for pentane? [/question] [solution] solution: [/solution]...
What would be the electron dot structure of a molecule of sulphur
[question] Question. What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? [solution] solution: The eight atoms of sulphur are joined together in the form of a puckered ring (crown shape). [/solution]...
What would be the electron dot structure
[question] Question. What would be the electron dot structure of carbon dioxide which has formula $\mathrm{CO}_{2}$ ? [solution] solution: In carbon dioxide molecule, the two oxygen atoms are bonded on either side with carbon atom by double bonds. Thus there are 2 double bonds in $\mathrm{CO}_{2}$. Carbon share its two electrons in the formation of a double bond with one oxygen atom and another two electrons with another oxygen atom. In this process, both the oxygen atoms and the carbon atom acq...