Common Chemical Compounds and Reactions

Potassium iodide has the chemical formula KI, formed from potassium (K) and iodine (I). It's used in iodized salt and radiation protection. NaCl is sodium chloride, NaOH is sodium hydroxide, and AgCl is silver chloride.

Potassium nitrate (KNO3) is commonly known as saltpeter (or saltpetre). It has been historically important as a component of gunpowder, food preservative, and fertilizer. The chemical formula KNO3 consists of potassium, nitrogen, and oxygen.

Sodium chloride (NaCl) is the chemical name for what we commonly call table salt or common salt. It's the salt most commonly used for food seasoning and preservation. 'Saltpeter' is potassium nitrate, not sodium chloride, making it incorrect.

Sodium bicarbonate is known by all these names: bicarbonate of soda, baking soda, and bicarb soda. They are different names for the same chemical compound (NaHCO3).

Sodium hypochlorite is the chemical name for household bleach, a common disinfectant and cleaning agent. Turpentine is a paint solvent, nail polish remover contains acetone, and natural gas is primarily methane.

Magnesium hydroxide is the active ingredient in milk of magnesia, which is used as a laxative and antacid. Therefore, both A and B are correct - magnesium hydroxide IS milk of magnesia, and it IS a laxative.

This is a duplicate of question 117649. Magnesium hydroxide is both milk of magnesia (a brand name) and a laxative (its function), making option C correct.

Calcium oxide (CaO) is commonly known as 'quicklime' or simply 'lime' in gardening. Gardeners use it to raise soil pH. Clay is a soil type, nitrate is a nitrogen compound, and chalk is calcium carbonate (different from calcium oxide).

Washing soda is sodium carbonate decahydrate (Na2CO3·10H2O) written as Na2CO3. Baking soda is sodium bicarbonate (NaHCO3). The formulas are correctly matched in option C with washing soda first and baking soda second.

Pearls are primarily calcium carbonate (CaCO3), which reacts with acids. Vinegar contains acetic acid (weak acid) that can dissolve calcium carbonate through the reaction: CaCO3 + 2CH3COOH → Ca(CH3COO)2 + H2O + CO2. While stronger acids like sulfuric and nitric would also work, vinegar is commonly cited in trivia about pearl dissolving.

Antifreeze used in vehicles is primarily ethylene glycol, which lowers the freezing point of water in cooling systems. Other glycol variants exist but ethylene glycol is the standard antifreeze compound.

Baking soda's chemical name is sodium bicarbonate (NaHCO3), a white crystalline compound used in baking and as an antacid. It should not be confused with sodium carbonate (washing soda) or calcium compounds.

Common table salt is sodium chloride (NaCl), the chemical compound used for food seasoning and preservation. The other chloride compounds listed serve different industrial purposes.

Chalk is chemically known as calcium carbonate (CaCO3), a soft white sedimentary rock. Sodium compounds (A, C) are incorrect because chalk contains calcium, not sodium. Calcium bicarbonate (B) is Ca(HCO3)2, which is soluble and chemically distinct from insoluble chalk.

Water's chemical formula is H2O, meaning two hydrogen atoms bonded to one oxygen atom. NaAlO2 is sodium aluminate, Al2O3 is aluminum oxide, and CaSiO3 is calcium silicate - none of these represent water.