A heavy trunk is lying on the floor. A boy applies a force of 100 N to pull it, but fails. Then a man pulls it by a force of 300 N, but fails. Then an athlete applies a force of 600 N and is able to pull it. What force does it prevent from moving in the first two cases ? What conclusions can you draw about the force from these three observations?

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).

Explain the following giving examples:

Saturated solution

Explain the following giving examples:

Pure substance

Explain the following giving examples:


Colloid