This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.
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Here are the solutions to the chemistry questions from the image: Question 1: A subatomic particle that is positively charged is a proton. A. Hydrogen ion (H^+) is an ion, not a fundamental subatomic particle. B. Electron is negatively charged. C. Proton is positively charged. D. Neutron has no charge. The final answer is C. Question 2: Metals less reactive than carbon can be extracted from their oxides by heating with carbon. Iron is less reactive than carbon. A. Aluminium is more reactive than carbon. B. Iron can be obtained by heating its oxide with carbon. C. Sodium is more reactive than carbon. D. Magnesium is more reactive than carbon. The final answer is B. Question 3: Transition metals typically form coloured ions in solution. Manganese is a transition metal. A. Manganese forms coloured ions (e.g., Mn^2+ is pale pink, MnO_4^- is purple). B. Nitrogen is a non-metal. C. Sulphur is a non-metal. D. Magnesium is an alkaline earth metal and forms colourless ions (Mg^2+). The final answer is A. Question 4: Sublimation is the process where a solid turns directly into a gas without passing through a liquid phase. A. Limestone (CaCO_3) decomposes on heating. B. Sodium Chloride (NaCl) melts. C. Copper (II) sulphate pentahydrate loses water of crystallization. D. Ammonium chloride (NH_4Cl) sublimes on heating. The final answer is D. Question 5: The kinetic theory of matter states that matter is composed of tiny particles that are in constant random motion. A. This describes general properties of matter. B. This describes atomic structure. C. This statement accurately describes the core idea of the kinetic theory. D. This describes states of matter, not the theory itself. The final answer is C. Question 6: Alkanes are saturated hydrocarbons and primarily undergo substitution reactions, where a hydrogen atom is replaced by another atom. A. Hydrogenation is for unsaturated compounds. B. Substitution is a characteristic reaction of alkanes (e.g., halogenation). C. Addition is for unsaturated compounds. D. Combustion is a general reaction for many organic compounds. The final answer is B. Question 7: The manufacture of sulphuric acid (Contact Process) involves several steps. A. This is a use of sulphuric acid, not a manufacturing step. B. Dissolving sulphur trioxide in water to give oleum is incorrect; SO_3 is dissolved in concentrated H_2SO_4 to form oleum. C. Burning of sulphur dioxide to give sulphur trioxide (2SO_2 + O_2 V_2O_5 2SO_3) is a key step in the Contact Process. D. Oleum is diluted with water to give sulphuric acid, not catalytically oxidized. The final answer is C. Question 8: When sodium is dropped in ethanol, it reacts to produce hydrogen gas (causing effervescence) and sodium ethoxide (CH_3CH_2ONa), which is a strong base. A. Sodium reacts, it doesn't just dissolve. B. Effervescence occurs, but hydrogen gas is not pungent. C. The resulting solution is alkaline due to sodium ethoxide, so it turns red litmus paper blue. This is a correct observation. D. Sodium ethoxide is produced, not sodium hydroxide. The final answer is C. Question 9: Polythene (polyethylene) is widely used for making plastic bags and is also an excellent electrical insulator. A. Terylene is used for fabrics and bottles. B. Polythene is suitable for packaging bags and electrical insulation. C. Polystyrene is used for disposable cups and insulation boards. D. Nylon is used for fibers and ropes. The final answer is B. Question 10: Electrolysis is a key process in the manufacture of certain heavy chemicals, particularly strong bases and reactive metals/non-metals. A. Sodium hydroxide (NaOH) is manufactured by the electrolysis of brine (chlor-alkali process). B. Sulphuric acid (H_2SO_4) is made by the Contact Process, which does not involve electrolysis. C. Nitric acid (HNO_3) is made by the Ostwald process, which does not involve electrolysis. D. Copper (Cu) is extracted from ores, often refined by electrolysis, but NaOH is a more direct fit for "manufacture involves electrolysis" as a primary production method for the bulk chemical. The final answer is A. Question 11: "Evolve steamy white fumes with PCl_5" indicates the presence of an -OH group (alcohol or carboxylic acid). "Equally evolve a colourless gas with sodium carbonate" indicates the presence of a carboxylic acid group (-COOH), as carboxylic acids react with carbonates to produce CO_2 gas. Alcohols do not react with sodium carbonate. Therefore, we are looking for a carboxylic acid. A. CH_3CH_2CH_2OH is an alcohol. B. CH_3CH=CH(OH) is an unstable enol. C. $CH