An alloy cannot be separated into its constituents by physical methods but still it is considered a homogeneous mixture. Explain.
Alloys are considered as homogeneous mixtures because,
(i) The composition of an alloy is uniform throughout its mass.
(ii) It shows the properties of its constituents and can have variable composition of its constituents.
Which separation techniques will you apply for the separation of the following?
Different pigments from an extract of flower petals.
Which separation techniques will you apply for the separation of the following?
Butter from curd.
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).
|
Substance Dissolved |
Temperature in K |
||||
|
283 |
293 |
313 |
333 |
353 |
|
|
Potassium nitrate |
21 |
32 |
62 |
106 |
107 |
|
Sodium chloride |
36 |
36 |
36 |
37 |
37 |
|
Potassium chloride |
35 |
35 |
40 |
46 |
54 |
|
Ammonium chloride |
24 |
37 |
41 |
55 |
66 |
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.
|
Substance Dissolved |
Temperature in K |
||||
|
283 |
293 |
313 |
333 |
353 |
|
|
Potassium nitrate |
21 |
32 |
62 |
106 |
107 |
|
Sodium chloride |
36 |
36 |
36 |
37 |
37 |
|
Potassium chloride |
35 |
35 |
40 |
46 |
54 |
|
Ammonium chloride |
24 |
37 |
41 |
55 |
66 |
Mock Test Series
