Question

Which of the following is not correct? (a) ozone is used to identify the presence of unsaturation in alkenes (b) sodium thiosulphate reacts with iodine to form sodium suphate (c) iodine oxidizes sodium thiosulphate to sodium tetrathionate (d) sodium thiosulphate is soluble in water

Short answer

Statement (b) is not correct.

Step-by-step solution

Analyze each statement

Review each option one by one, focusing on the accuracy based on chemical principles and reactions.

Evaluate statement (a)

Statement (a) is about the reaction of ozone with alkenes. Ozone reacts with alkenes in a process called ozonolysis to identify unsaturation. Thus, statement (a) is correct.

Evaluate statement (b)

Statement (b) claims sodium thiosulphate reacts with iodine to form sodium sulphate. The correct reaction is: iodine reacts with sodium thiosulphate to form sodium tetrathionate, not sodium sulphate. Therefore, statement (b) is incorrect.

Evaluate statement (c)

Statement (c) states that iodine oxidizes sodium thiosulphate to sodium tetrathionate. The chemical equation is 2I_2 + 2Na_2S_2O_3 → 2NaI + Na_2S_4O_6. This statement is correct.

Evaluate statement (d)

Statement (d) indicates that sodium thiosulphate is soluble in water, which is true as sodium thiosulphate is indeed highly soluble in water.

Key concepts

Understanding Ozonolysis in Alkenes

Ozonolysis is a vital reaction in organic chemistry, especially when identifying unsaturation within alkenes. During ozonolysis, ozone (\(O_3\)) reacts with alkenes, cleaving the carbon-carbon double bonds. This transformative reaction results in the formation of aldehydes or ketones depending on the substituents linked to the carbon atoms involved. For instance, when ozone interacts with an alkene with general formula \(R_2C=CR_2\), ozonolysis typically results in two carbonyl groups.- Alkenes are unsaturated hydrocarbons with one or more double bonds.- The cleavage during ozonolysis is beneficial in identifying points of unsaturation.- Ozonolysis product analysis helps deduce the structure of the original alkene.In educational contexts like the JEE Chemistry curriculum, understanding ozonolysis is essential, as it illustrates both the reactivity and structural analysis of organic compounds.

Reactions Involving Sodium Thiosulphate

Sodium thiosulphate (\(Na_2S_2O_3\)) serves as a versatile reagent in many chemical reactions. It readily reacts with iodine. However, the reaction does not yield sodium sulphate as incorrectly stated in some contexts but instead forms sodium tetrathionate according to the equation:\[mundobc Equation: 2I_2 + 2Na_2S_2O_3 \rightarrow 2NaI + Na_2S_4O_6\]- Sodium thiosulphate is often used as a reducing agent in these reactions.- The product sodium tetrathionate (\(Na_2S_4O_6\)) is derived from the transfer of electrons during the chemical conversion.In various educational settings, emphasizing the specific outcomes of reactions involving sodium thiosulphate clarifies misconceptions rooted in improper chemical equation understanding.

Iodine and Sodium Thiosulphate

The interaction between iodine (\(I_2\)) and sodium thiosulphate is an intriguing oxidation-reduction reaction crucial for understanding redox chemistry. Iodine acts as an oxidizing agent, converting sodium thiosulphate into sodium tetrathionate while being reduced to sodium iodide:\[2I_2 + 2Na_2S_2O_3 \rightarrow 2NaI + Na_2S_4O_6\]- \(Na_2S_2O_3\) is oxidized, showing its ability to engage in redox processes effectively.- This reaction is often employed in titration methods to determine the concentration of iodine.For students studying JEE Chemistry, mastering such reactions highlights concepts of electron transfer and the function of reagents like sodium thiosulphate in analytic chemistry.

Solubility Characteristics of Compounds

Solubility is a fundamental property that dictates how substances dissolve in solvents, influencing their behavior in various chemical processes. Sodium thiosulphate (\(Na_2S_2O_3\)) is highly soluble in water, making it a convenient reagent for many laboratory applications. - Solubility is affected by intermolecular forces, temperature, and the nature of solvents.- High solubility ensures sodium thiosulphate is readily available for reaction without extensive preparation.Understanding solubility helps students rationalize the physical state and availability of compounds like sodium thiosulphate in chemical reactions, critical for experimental setups in both educational and practical chemistry environments.

Analyzing Chemical Equations

Chemical equation analysis is a fundamental skill for any chemistry student and is crucial for correctly interpreting reactions such as those involving iodine and sodium thiosulphate. - Analysis begins with ensuring chemical equations are balanced, reflecting the conservation of mass. - Identifying the type of reaction taking place (e.g., redox, endothermic, or exothermic) enhances understanding. - Correct interpretation can prevent misconceptions, such as assuming incorrect products like sodium sulphate from certain reactions. Students in JEE Chemistry need to be adept at dissecting chemical equations, as it sharpens their ability to not only predict reaction outcomes but also analyze the underlying principles guiding chemical processes.