In Dumas' method 292text mg$292\text{ mg}$ of an organic compound released 50text mL$50\text{ mL}$ of nitrogen gas (textN_2)$(\text{N}_2)$ at 300text K$300\text{ K}$ temperature and 715text mm Hg$715\text{ mm Hg}$ pressure. [cite: 435, 451] The percentage composition of 'N' in the organic compound is dots$\dots$ % (Nearest integer) [cite: 452, 455] (Aqueous tension at 300text K = 15text mm Hg$300\text{ K} = 15\text{ mm Hg}$)

### Core Logic Statement I is fully accurate: Dumas method is standardly applied for estimating elemental nitrogen across structural compounds. Statement II is incorrect: The reaction leading to ammonium sulphate generation by intense thermal heating alongside concentrated mathrmH_2mathrmSO_4$\mathrm{H}_2\mathrm{SO}_4$ describes the **Kjeldahl method**, not the Dumas strategy. The Dumas process instead relies on burning carbonaceous compounds explicitly with copper oxide to convert nitrogen cleanly into free gas (N_2$N_2$). ### Pattern Recognition Dumas method collects element gas N_2$N_2$ via volumetric analysis; Kjeldahl maps digestions via standard (mathrmNH_4)_2mathrmSO_4$(\mathrm{NH}_4)_2\mathrm{SO}_4$ pathways. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques

### Related Formula Direct phase transition without passing through an intermediate liquid phase defines sublimation: textSolid rightleftharpoons textVapour$$\text{Solid} \rightleftharpoons \text{Vapour}$$ ### Core Logic The schematic diagram represents a solid turning directly into vapor on heating, which then reverts back to a solid phase upon cooling. This distinct behavior isolates sublimable solids from non-sublimable impurities. ### Step 1: Identification This transformation perfectly defines the laboratory purification process known as **Sublimation**. ### Pattern Recognition Look for the skipping of the liquid state entirely: Solid rightarrow$\rightarrow$ Vapour rightarrow$\rightarrow$ Solid. Common examples include camphor, naphthalene, benzoic acid, and iodine. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques

### Related Formula Isomers share an identical molecular formula but differ in structural arrangement or functional groups: textSame M_f neq textSame structural layout$$\text{Same } M_f \neq \text{Same structural layout}$$ ### Core Logic Evaluating the structural parameters: - **Statement I**: Oxacyclobutane (a cyclic ether) and prop-2-en-1-ol (an unsaturated alcohol) both possess the molecular formula C_3H_6O$C_3H_6O$. They are functional/ring-chain isomers, so Statement I is true. - **Statement II**: Propan-1-amine (1^circ$1^\circ$ amine) and N-methylethanamine (2^circ$2^\circ$ amine) both share the molecular formula C_3H_9N$C_3H_9N$. Because primary, secondary, and tertiary amines contain different functional groups, they act as functional group isomers. Thus, Statement II is true. ### Step 1: Conclusion Match Since both structural statements are valid, both Statement I and Statement II are true.

### Pattern Recognition Always remember that 1^circ$1^\circ$, 2^circ$2^\circ$, and 3^circ$3^\circ$ amines are classified as *different functional groups* in IUPAC nomenclature. Consequently, structural shifts between them with a constant carbon count represent functional group isomerism. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques

### Related Formula Nucleophiles are electron-rich species containing lone pairs of electrons or pi$\pi$-bonds that can donate an electron pair to an electrophilic center. ### Core Logic Let us examine each species: * mathrmNH_3$\mathrm{NH}_3$: Contains a lone pair on nitrogen rightarrow$\rightarrow$ Nucleophile * mathrmPhSH$\mathrm{PhSH}$: Contains lone pairs on sulfur rightarrow$\rightarrow$ Nucleophile * (mathrmH_3mathrmC)_2mathrmS$(\mathrm{H}_3\mathrm{C})_2\mathrm{S}$: Contains lone pairs on sulfur rightarrow$\rightarrow$ Nucleophile * mathrmH_2mathrmC=mathrmCH_2$\mathrm{H}_2\mathrm{C}=\mathrm{CH}_2$: Contains a nucleophilic pi$\pi$-bond rightarrow$\rightarrow$ Nucleophile * stackrelominusmathrmOmathrmH$\stackrel{\ominus}{\mathrm{O}}\mathrm{H}$: Negatively charged with lone pairs rightarrow$\rightarrow$ Nucleophile * mathrmH_3mathrmO^oplus$\mathrm{H}_3\mathrm{O}^{\oplus}$: Electron deficient, positively charged oxygen cannot donate electrons rightarrow$\rightarrow$ Electrophile * (mathrmCH_3)_2mathrmCO$(\mathrm{CH}_3)_2\mathrm{CO}$: Carbonyl carbon is electrophilic * >=mathrmNCH_3$>=\mathrm{NCH}_3$: Imine carbon is electrophilic Thus, the total number of nucleophiles is 5. ### Pattern Recognition Neutral molecules with lone pairs (N, S) or alkenes/alkynes with available pi$\pi$-electrons operate as good nucleophiles, along with full anions. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques

### 1. RELATED FORMULA IUPAC Rules select the longest principal carbon chain and number it to give substituents the lowest possible locants. ### 2. EXECUTION **CORE LOGIC** Let's systematic decode each name : * (A) Longest chain contains 7 carbons (heptane) with an ethyl group at position 3 and a methyl group at position 5 rightarrow$\rightarrow$ 3-Ethyl-5-methylheptane (II) . * (B) C expanded yields a 7 carbon main chain with two methyl groups at carbon-4 rightarrow$\rightarrow$ 4,4-Dimethylheptane (III) . * (C) 5-carbon diene numbered from the left double bond side rightarrow$\rightarrow$ 2-Methyl-1,3-pentadiene (IV) . * (D) 5-carbon alkene starting from the double bond end rightarrow$\rightarrow$ 4-Methylpent-1-ene (I) . Therefore, matching sequence: (A)-(II), (B)-(III), (C)-(IV), (D)-(I). ### 3. PATTERN RECOGNITION Expanding compressed groupings such as mathrm(C_3H_7)_2$\mathrm{(C_3H_7)_2}$ prevents errors regarding parent chain carbon counts. ### 4. EVALUATION RUBRIC / MODEL ANSWER null ### 5. CHAPTER MIX Class 11 Chemistry: Organic Chemistry - Some Basic Principles and Techniques