181. The most commonly used method for the refining of impure metals is electrolysis. Selection Refining Permeation De-selection Answer: Refining 182. After being left in the air for some time, _______ turns black. Gold Silver Copper Iron Answer: Copper 183. A homogeneous mixture of two or more metals or a metal and a non-metal is […]

161. The atomic number of chlorine is _______. 12 15 17 14 Answer: 17 162. In graphite, each carbon atom bonds with other carbon atoms in the same plane, forming a hexagonal arrangement. Four Three Two Five Answer: Three 163. Generally, _______ have a sweet fragrance. Aldehydes Ketones Ethers Esters Answer: Esters 164. Rock salt

141. Precipitation reactions produce _______. Organic Compounds Oils and Fats Soluble Salts Insoluble Salts Answer: Insoluble Salts 142. What happens when sulfuric acid is mixed with zinc? Zinc sulfate and water are formed Sulfur and ZnO are formed H₂ gas and ZnSO₄ are formed No reaction occurs Answer: H₂ gas and ZnSO₄ are formed 143.

121. The most flexible metal is? Silver Platinum Copper Gold Answer: Silver 122. The reaction of Iron (III) Oxide with _______ is used for joining railway tracks or broken machine parts. Magnesium Aluminum Manganese Zinc Answer: Aluminum 123. The oxide of _______ cannot be reduced by carbon. Al Zn Sn Fe Answer: Al 124. Coating

101. Baking powder is a mixture of baking soda and a food acid, namely: Gluconic Acid Maleic Acid Tartaric Acid Fatty Acid Answer: Tartaric Acid 102. Washing soda is: Na₂CO₃.5H₂O Na₂CO₃.H₂O Na₂CO₃.10H₂O Na₂CO₃ Answer: Na₂CO₃.10H₂O 103. Some metals can be beaten into thin sheets. This property is called: Metallic Lustre Flexibility Resonance Malleability Answer: Malleability

81. Soap is made by alkaline hydrolysis of Salt Carboxylic acid Ester Alcohol Answer: Ester 82. From which water source does soap clean best? Tap Rain Well Hand pump Answer: Rain 83. A compound with the same molecular formula but different structural formula is called Isomerism Isotope Isobar Isotone Answer: Isomerism 84. The IUPAC name

61. Elements with the same atomic number but different mass numbers are called: Isobars Isotopes Isotones None of these Answer: Isotopes 62. Elements A, B, C, and D have atomic numbers 12, 13, 15, and 3, respectively. Which element cannot form a cation? A B C D Answer: C 63. The number of electrons in

41. ___ is: Catechol Resorcinol Cresol Quinone Answer: Catechol 42. Acetylation of salicylic acid produces: Picric acid Aspirin Cumene Salicylaldehyde Answer: Aspirin 43. The hybridization in a C₂H₂ molecule is: sp³ sp² sp sp³d Answer: sp 44. Aldehydes without an α-hydrogen atom undergo self-oxidation and reduction reaction when heated with: Concentrated acid Concentrated alkali Dilute

21. All enzymes that use ATP for phosphate transfer require it as a cofactor. Sodium Potassium Calcium Magnesium Answer: Magnesium 22. Borax is: Na₂B₄O₇.10H₂O Na₂B₄O₇.5H₂O Na₂B₄O₇.H₂O Na₂B₄O₇.½H₂O Answer: Na₂B₄O₇.10H₂O 23. Under isothermal conditions, __________ = 0 for an irreversible process. ΔU ΔH ΔS ΔV Answer: ΔU 24. ZSM-5 (a type of zeolite) is used to

1. Fat-soluble vitamin is Vitamin A Vitamin C Vitamin B₁ Vitamin B₂ Answer: Vitamin A 2. The hormone that increases blood glucose level is Insulin Glucagon Glucocorticoid Mineralocorticoid Answer: Glucagon 3. In the reaction 2KClO₃ → 2KCl + 3O₂, the catalyst used is Fe₂O₃ PbCl₂ PdCl₂ MnO₂ Answer: MnO₂ 4. In Ni(CO)₄ and Fe(CO)₅, the