Okay, I understand. For chemistry practical questions, especially qualitative analysis, the key is to systematically link your observations to chemical inferences. Here's a general approach to follow: 1. Record/Interpret Observations: Carefully note exactly* what you see at each stage of the experiment. This includes color changes, precipitate formation (and its color/solubility), gas evolution (and its properties like smell or effect on litmus), and temperature changes. If the question provides a table, fill in the observations accurately. If you're asked to predict, think about the expected outcome for common ions/compounds. 2. Deduce Inferences: Based on each observation, make a specific chemical deduction. For example: "White precipitate soluble in excess aqueous $\text{NaOH}$" ⟹ "Presence of $\text{Zn}^{2+}$ or $\text{Al}^{3+}$." "Gas turns moist red litmus blue" ⟹ "Ammonia gas ($\text{NH}_3$) produced." "Green precipitate" ⟹ "Presence of $\text{Fe}^{2+}$." Use your knowledge of common tests for cations, anions, and gases. 3. Identify Unknowns: Combine all your inferences from different tests to identify the unknown substance (e.g., compound E, solution X). Look for consistent deductions across multiple tests. 4. Write Equations (if required): Sometimes you'll be asked to write ionic or full chemical equations for the reactions that occurred. Ensure they are balanced and include state symbols. Example from your previous question (Compound E): Let's say the question asks you to identify Compound E based on the test: "To $2\text{cm}^3$ of a solution of E, add aqueous $\text{AgNO}_3$ followed by dil $\text{HNO}_3$ and finally, conc $\text{NH}_3$." Observation (Assumed for explanation): A white precipitate forms with $\text{AgNO}_3$. This precipitate is insoluble in dilute $\text{HNO}_3$ but dissolves in concentrated $\text{NH}_3$. Inference 1 (from $\text{AgNO}_3$): Formation of a white precipitate with $\text{AgNO}_3$ suggests the presence of a halide ion (e.g., $\text{Cl}^-$, $\text{Br}^-$, $\text{I}^-$) or other anions like $\text{SO}_4^{2-}$, $\text{CO}_3^{2-}$. Inference 2 (from dil $\text{HNO}_3$): The precipitate being insoluble in dilute $\text{HNO}_3$ rules out carbonates and sulfites, and confirms it's likely a halide. Inference 3 (from conc $\text{NH}_3$): The precipitate dissolving in concentrated $\text{NH}_3$ is a characteristic test for silver chloride ($\text{AgCl}$). Silver bromide ($\text{AgBr}$) is sparingly soluble, and silver iodide ($\text{AgI}$) is insoluble. Conclusion: Compound E contains chloride ions ($\text{Cl}^-$). Do you want to continue with the specific questions from the photo you sent earlier, or would you like to discuss another type of practical question?