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❓ Concept Question How do we calculate total enthalpy change when water is cooled, frozen, and further cooled as ice? 🖼 Concept Image ✍️ Sho…

❓ Concept Question When a strong acid solution is diluted by adding equal volume of water, how does the pH change ? 🖼 Concept Image ✍️ Shor…

❓ Question Assertion (A): Elements and compounds are examples of pure substances. Reason (R): The properties of a compound are different from tho…

❓ Question Why are compounds called pure substances even though their properties are completely different from their constituent elements? ✍️ S…

❓ Concept Question In Group 14 elements, how do we determine whether ions like A 2 + A^{2+}  or B 4 + B^{4+}  behave as oxidising or reducing agen…

❓ Question Given complex: Co ⋅ 5 N H 3 ⋅ C l ⋅ S O 4 \text{Co} \cdot 5NH_3 \cdot Cl \cdot SO_4 Two isomers A and B: A gives white ppt with AgN…

❓ Question Why does a person feel heavier when a lift accelerates upward? 🖼️ Concept Image ✍️ Short Solution This is a pure Newton’s Secon…

❓ Question A man of mass 75 kg stands in a lift. The lift starts moving upward with an acceleration of 2 m/s² . Find the force exerted on him b…

❓ Question Among: Cr, Fe, Co, Ni Which metal has the lowest enthalpy of atomisation ? Find the number of valence electrons in that metal. 🖼 Q…

❓ Question Reaction: A ( g ) → 2 B ( g ) + C ( g ) A(g) \rightarrow 2B(g) + C(g) First order reaction Given: t (min) Pressure (mm Hg) 10 160 ∞ …