List of top Science Questions on Chemistry in Everyday Life

Give reasons for the following:
(I) Covalent compounds are poor conductor of electricity.
(II) Soap does not form lather in hard water.
(III) Carbon shows catenation but silicon does not.
Write chemical equations for the following :
(I) Oxidation of ethanol by acidified K₂Cr₂O₇.
(II) Hydrogenation of ethene.
Mohan heated ethanol with a compound 'X' in the presence of a few drops of conc. \( H_2SO_4 \) and observed a sweet smelling compound 'Y' is formed. When 'Y' is treated with sodium hydroxide it gives back ethanol and a compound 'Z'.
(i) Identify 'X', 'Y' and 'Z'.
(ii) Write the role of conc. \( H_2SO_4 \) in the reaction.
(iii) Write the chemical equations involved and name the reactions.
Assertion (A): Carbon shares its valence electrons with other atoms of carbon or with atoms of other elements.
Reason (R): The shared electrons belong to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.
Why does one feels pain and irritation when stung by honey-bee?
Rubbing of baking soda on the stung area gives relief. How?
What happens when : (a) An iron nail is dipped in copper (II) sulphate solution ?
(b) Potassium iodide solution is mixed with lead nitrate solution ?
(c) Silver chloride is exposed to sunlight ?
Write balanced chemical equations to support your answer.
Explain chlor-alkali process with chemical equation. Name the products formed at anode and cathode.
Which one of the following can be used as an acid-base indicator by a visually impaired (blind) student?
The hydrocarbons with general formula \( C_nH_{2n} \) represents:
Which of the following is a poor conductor of electricity?
The natural sources of oxalic acid, lactic acid and methanoic acid respectively are:
The gases evolved on heating lead (II) nitrate crystals are :
(i) \( \text{AgNO}_3 + \text{NaCl} \rightarrow \text{NaNO}_3 + \text{AgCl} \)
(ii) \( \text{K}_2\text{SO}_4 + \text{BaCl}_2 \rightarrow \text{BaSO}_4 + 2\text{KCl} \)
Which of the following options clearly describes both the reactions?
Homologous series in the following are : (i) $C_2H_4$ and $C_3H_6$
(ii) $CH_3OH$ and $CH_3CHO$
(iii) $HCHO$ and $CH_3CHO$
The correct option in context of the above is :
Which of the following metal forms hydrogen gas with cold water?
Complete the following chemical equation:
________ + PCl5 → CH3COCl + POCl3 + HCl

Match the Chemical Substances with Their Applications

Column A

a. Acetic acid

b. Ethanol

c. Caustic soda

d. Detergents

Column B

i. In the formation of soap

ii. In making denatured spirit

iii. In the formation of vinegar

iv. In cleaning clothes

Tally of Substances and Their Applications

Given Substances in Column A:

a. Plaster of Paris

b. Caustic soda

c. Sodium bicarbonate

d. Bleaching powder

Applications in Column B:

i. Formation of soap

ii. Antibacterial

iii. Formation of an idol

iv. Used for bleaching

Explain the following:

Cleansing action of soap
Calcination and Roasting
Activity series of metals
The chemical formula of Plaster of Paris is:
Pure air is: