Which disinfectant is used in water treatment that does not leave any residual taste or odor? MCQ with Answer and Explanation

Explanation:
Atomic number = 2+8+7=17 (chlorine). Period = number of shells = 3. Valence electrons = 7 → Group 17 (10+7 for p-block). Group 18 has 8 valence electrons.

Explanation:
Crude petroleum is heated and the vapors are passed through a fractionating column where they condense at different levels according to boiling points. Fractions: petrol (40-120°C), kerosene (150-250°C), diesel (250-350°C), lubricating oil, etc. This is a continuous process. The column has trays and maintains temperature gradient. Simple distillation cannot separate close boiling mixtures.

Explanation:
Nitric acid (HNO₃) is used for nitration reactions to produce explosives such as TNT (trinitrotoluene), nitroglycerin, and dynamite. Sulfuric acid acts as a catalyst/dehydrating agent in nitration mixtures (mixed acid). HCl is used for cleaning and chemical synthesis. Acetic acid is organic acid. Nitric acid provides nitro groups (-NO₂).