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Explain the nature of the covalent bond using the bond formation in CH₃Cl

Answer: Chloroform is an organic chemical compound initially employed as an ideal anaesthetic. It is a colourless, sweet-smelling dense liquid... View Article

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that (a) the food is not cooked completely. (b) the fuel is not burning completely. (c) the fuel is wet. (d) the fuel is burning completely.

Answer: (b) the fuel is not burning completely. If the bottom of the vessel becomes blackened on the outside when cooking, the fuel is not... View Article

Butanone is a four-carbon compound with the functional group (a) carboxylic acid (b) aldehyde (c) ketone (d) alcohol

Answer: (c) ketone In ketones, the carbonyl group has 2 hydrocarbon groups attached to it. These can be either the ones containing benzene... View Article

Ethane, with the molecular formula C₂H₆ has (a) 6 covalent bonds. (b) 7 covalent bonds. (c) 8 covalent bonds. (d) 9 covalent bonds

Answer: (b) 7 covalent bonds Ethane is a saturated hydrocarbon in gaseous form. Ethane is the second most common alkane, followed by methane.... View Article

People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?

Answer: Soap reduces water's surface tension. The soap's long chain non-ionic hydrocarbon group binds to oil or grease droplets, softening them... View Article

Would you be able to check if water is hard by using a detergent?

Answer: The water with naturally present minerals like magnesium and calcium with detectable amount is called hard water. These minerals are... View Article

What are oxidising agents?

Answer: An oxidizing agent (oxidizer or oxidant) is a chemical species that tends to oxidize other substances, i.e. cause an increase in the... View Article

How would you distinguish experimentally between an alcohol and a carboxylic acid?

Answer: Carboxylic acids emit carbon dioxide gas when they react with Sodium Carbonate, turning lime water milky, whereas alcohols do not. This... View Article

A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?

Answer: Since the production of heat is very necessary for welding metals, a mixture of oxygen and ethyne is burned instead of ethyne and air.... View Article

Why is the conversion of ethanol to ethanoic acid an oxidation reaction?

Answer: It is an oxidation reaction as ethanol is converted to ethanoic acid since the hydrogen atom is removed and oxygen is added. 1st step To... View Article

Draw the structures for the following compounds. (i) Ethanoic acid (ii) Bromopentane (iii) Butanone (iv) Hexanal

Answer: The covalently bonded carbon-containing compounds called organic compounds are substantial for life on earth. The specific branch of... View Article

What will be the formula and electron dot structure of cyclopentane?

Answer: Electron dot structures or Lewis dot formula can be drawn if the molecular formula of the compound is known. It defines the nature of... View Article

What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?

Answer: Carbon forms a range of substances with a number of other elements; these compounds are known as carbon compounds. Carbon forms the basic... View Article

What would be the electron dot structure of a molecule of Sulphur which is made up of eight atoms of Sulphur? (Hint – The eight atoms of Sulphur are joined together in the form of a ring).

Answer: Sulphur has an atomic number of 16 and an electronic configuration of 2,8,6. The valance electrons on the sulphur atom are six. The... View Article

State whether the following statements are true or false. (a) An electric motor converts mechanical energy into electrical energy. (b) An electric generator works on the principle of electromagnetic induction. (c) The field at the center of a long circular coil carrying current will be parallel straight lines. (d) A wire with a green insulation is usually the live wire of an electric supply.

Answer: (1) False An electric motor converts electrical energy into mechanical energy. An electric motor is a device used to convert... View Article

At the time of short circuit, the current in the circuit (1) reduces substantially. (2) does not change. (3) increases heavily. (4) vary continuously.

Answer: (3) Increases heavily A short circuit occurs when the current in the circuit rises rapidly and the electrical connection draws an... View Article

In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?

Answer: Calcium has an atomic number of 20, and thus has an electronic configuration, Ca (Z = 20) = 1s2 2s2 2p6 3s2 3p6 4s2 The element having... View Article

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3	4	5	6	7	8	9
10	11	12	13	14	15	16
17	18	19	20	21	22	23
24	25	26	27	28	29	30
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