Classify the following as a chemical or physical change.

(i) Cutting of trees; (ii) Melting of butter in a pan; (iii) An almirah gets rusted; (iv) Water boils to form steam; (v) Electric current is passed through water and it is broken down into hydrogen and oxygen gas; (vi) Dissolving salt in water.

Write the steps you would use for making tea. Use the words—solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).