Question 1

Which of the following is the main active ingredient in common antacids used to neutralize stomach acid?

Accepted Answer

Calcium carbonate (CaCO₃) is a weak base that reacts with HCl in the stomach to form CO₂, H₂O, and Ca²⁺ ions, effectively neutralizing gastric acid.

Question 2

What is the primary chemical compound responsible for the bleaching action in household bleach?

Accepted Answer

Sodium hypochlorite (NaOCl) is the active bleaching agent that oxidizes and breaks down coloured dyes and stains on fabrics.

Question 3

Which chemical compound is commonly used as a preservative in food items like jams and pickles?

Accepted Answer

Sodium benzoate inhibits the growth of microorganisms by lowering pH and preventing microbial fermentation in preserved foods.

Question 4

What is the chemical formula of the compound used in LPG (Liquefied Petroleum Gas) that is odorless and requires an odorant for safety?

Accepted Answer

Propane (C₃H₈) and butane (C₄H₁₀) are the primary components of LPG; mercaptan (C₂H₆S) is added as an odorant for leak detection.

Question 5

Which of the following is the active disinfectant in antiseptic solutions used for wound cleaning?

Accepted Answer

Iodine tincture acts as an oxidizing agent that kills bacteria, viruses, and fungi by disrupting their cell membranes and protein synthesis.

Question 6

Which chemical compound is commonly used as a preservative in food items to prevent bacterial growth?

Accepted Answer

Sodium benzoate is a widely used food preservative that inhibits microbial growth by lowering pH and disrupting bacterial cell membranes.

Question 7

Baking soda (sodium bicarbonate) releases carbon dioxide gas when heated. Which equation represents this thermal decomposition?

Accepted Answer

Upon heating, sodium bicarbonate decomposes to produce sodium carbonate, water, and carbon dioxide gas, which makes baked goods rise.

Question 8

Which chemical is used in toothpaste to prevent tooth decay by strengthening tooth enamel?

Accepted Answer

Sodium fluoride and other fluoride compounds are added to toothpaste to promote remineralization and prevent dental caries.

Question 9

What is the primary purpose of using antacids like calcium carbonate in everyday life?

Accepted Answer

Antacids containing calcium carbonate react with hydrochloric acid in the stomach (CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂) to neutralize excess acid and reduce heartburn.

Question 10

Which compound is added to water in swimming pools to disinfect and kill harmful microorganisms?

Accepted Answer

Chlorine and hypochlorite compounds are oxidizing agents that effectively eliminate bacteria, viruses, and algae in pool water.

Question 11

Vinegar (acetic acid, CH₃COOH) is used for cleaning household surfaces. What is the chemical basis for its cleaning action?

Accepted Answer

Acetic acid's acidic nature helps dissolve limescale, soap residue, and grease by reacting with and breaking down these deposits.

Question 12

Which substance is commonly used as a desiccant (drying agent) in packaging to keep products dry and prevent moisture damage?

Accepted Answer

Silica gel is a porous material that absorbs moisture effectively and is widely used in packaging electronics, medicines, and other moisture-sensitive products.

Question 13

Aspirin (acetylsalicylic acid) works as a pain reliever and anti-inflammatory agent. Which functional group in its structure is primarily responsible for its acidic properties?

Accepted Answer

The carboxylic acid group in aspirin donates protons and contributes to its acidic nature and pharmaceutical activity in reducing inflammation and pain.

Question 14

Hard water contains dissolved calcium and magnesium ions. When soap is added to hard water, a white precipitate forms instead of lather. Which chemical reaction explains this phenomenon?

Accepted Answer

Soap (long-chain fatty acid salts) reacts with Ca²⁺ and Mg²⁺ ions to form insoluble precipitates, reducing lathering efficiency in hard water.

Question 15

Bleaching powder is widely used for disinfection of drinking water in India. If bleaching powder contains Ca(OCl)₂ as the active ingredient and 0.5 kg of bleaching powder is used to disinfect 1000 liters of water, what is the approximate concentration of hypochlorous acid (assuming 35% purity of Ca(OCl)₂ in bleaching powder)?

Accepted Answer

0.5 kg × 35% = 175 g of Ca(OCl)₂; dissolved in 1000 L yields approximately 175 mg/L concentration of active chlorine species.

Question 16

In the preparation of common salt (NaCl) by the Solvay process, ammonia plays a crucial role. Which of the following best describes why ammonia is essential in this industrial process used in everyday salt production?

Accepted Answer

Ammonia reduces NaCl solubility in saturated brine, causing common salt to crystallize and precipitate, which is the fundamental principle of the Solvay process.

Agniveer Army Technical Chemistry in Everyday Life

Chemistry in Everyday Life — Practice Questions