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Class xii Subject :- Chemistry  Chapter :- Chemical kinetics  INTEXT QUESTION  Intext Question 3.1 Question  For the reaction R → P, the concentration of reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds. Answer Given: Initial concentration, [R]₁ = 0.03 M Final concentration, [R]₂ = 0.02 M Time, Δt = 25 minutes Change in concentration: Δ[R] = 0.02 − 0.03 = −0.01 M Average rate of reaction: rav = −Δ[R] / Δt In minutes: rav = 0.01 / 25 rav = 4.0 × 10⁻⁴ mol L⁻¹ min⁻¹ In seconds: 25 minutes = 25 × 60 = 1500 s rav = 0.01 / 1500 rav = 6.67 × 10⁻⁶ mol L⁻¹ s⁻¹ Final Answer: Average rate = 4.0 × 10⁻⁴ mol L⁻¹ min⁻¹ Average rate = 6.67 × 10⁻⁶ mol L⁻¹ s⁻¹ प्रश्न: R → P अभिक्रिया के लिए अभिकारक की सांद्रता 0.03 M से 25 मिनट में घटकर 0.02 M हो जाती है। औसत  वेग की गणना मिनट तथा सेकंड दोनों इकाइयों में कीजिए। उत्तर: दिया गया: प्रारंभिक सांद्रता, [R]₁ = 0.03 M अंतिम सांद्रता, [R]₂ = 0.02 ...

Class :- XII Subject :- Chemistry  Chapter :- Electrochemistry                    ( वैद्युत रसायन )    Intext Questions Intext Question 2.1 Question  How would you determine the standard electrode potential of the system Mg²⁺ | Mg? Answer  The standard electrode potential of Mg²⁺ | Mg can be determined by connecting the magnesium half-cell with the standard hydrogen electrode (SHE). Procedure : Prepare a half-cell by dipping a magnesium rod in 1 M Mg²⁺ solution. Connect this half-cell with the standard hydrogen electrode: H₂ gas at 1 bar H⁺ ion concentration = 1 M Temperature = 298 K Measure the emf of the cell. Cell representation: Mg(s) | Mg²⁺(1 M) || H⁺(1 M) | H₂(1 bar) | Pt Mg(s) | Mg²⁺(1 M) || H⁺(1 M) | H₂(1 bar) | Pt Since the standard electrode potential of SHE is 0 V, the emf of the cell gives the standard electrode potential of Mg²⁺ | Mg, which is –2.36 V. प्रश्न निकाय Mg²⁺ | Mg  का मानक इलेक्ट्रोड ...