Question

1. Preparation of: Unit-I

a) a true solution of common salt, sugar and alum

b) a suspension of soil, chalk powder and fine sand in water

c) a colloidal solution of starch in water and egg albumin/milk in water and distinguish

between these on the basis of

●transparency

● filtration criterion

●stability

CAN ANY ONE PLEASE EXPLAIN WHAT THIS QUESTION IS ASKING TO DO​

Answer 1

$\huge\colorbox{cyan}{Verified Answer}$

• A true solution is transparent and stable. Step 1: Three beakers are taken and 100 ml of water is added in each of them and labelled them as A, B and C respectively. Step 2: 10g of finely powdered common salt, sugar and alum is added in each beaker separately. Step 3: Solution is stirred with the help of glass rod.

• Suspension is a heterogeneous mixture of particles from which the particles are settled down with time. Chalk powder does not dissolve in water at all.It just forms suspension in water and after some time settles down under the influence of gravity.

• Break the outer shell of the egg by striking it with a glass rod and collect its colour less liquid along with yellow yolk. Decant the colourless liquid into another beaker. This colourless liquid is known as egg albumin. take 15-20 minutes.

● a colloidal solution of starch in water and egg albumin in water and distinguish between these on the basis of: transparency; filtration criterion ...

● The basic requirements for filtration are: (1) a filter medium; (2) a fluid with suspended solids; (3) a driving force such as a pressure difference to cause fluid to flow; and (4) a mechanical device (the filter) that holds the filter medium, contains the fluid, and permits the application of force.

● the quality, state, or degree of being stable: such as. a : the strength to stand or endure : firmness. b : the property of a body that causes it when disturbed from a condition of equilibrium or steady motion to develop forces or moments that restore the original condition.

Full answer ⬆⬆⬆⤴

Answer 2

Complete answer:

(a) The true solution is homogeneous mixture which cannot be separated by the process of filtration. A true solution is said to be stable and transparent. Three beakers are taken in which 100mL water is added and are labelled as A,B,C. Then the addition of 10g powered salt, sugar and alum is added to each beaker. For transparency we will add a small strip of cellophane paper and paste then on each test tube and observe the colour. The colour spot is seen clearly, which means true solutions are transparent. For filtration all the contents in beakers are filtered and observing we see no residue is seen so solid particles are not able to separate from the true solution. For stability leave the test tube without disturbing it for 25 minutes, wesee that no change has occurred. This means true solutions are stable.

(b) For the transparency, filtration and stability in colloidal solution we will take three beakers in which 100mL water is added and are labelled as A,B,C. Then the addition of 10g of fine sand, chalk powder and soil is added in each beaker. For transparency we will add a small strip of cellophane paper and paste then on each test tube and observe the colour. The colour spot is not seen clearly, which means colloidal solutions are not transparent.. For filtration all the contents in beakers are filtered and observing we see that the residue is seen so solid particles are able to separate from colloidal solutions. For stability leave the test tube without disturbing it for 25minutes, we see that settlement of solid particles has occurred. This means colloidal solutions are not stable.

(c) For the colloidal solution of starch in water 1% of dry corn starch is mixed with 3mL of distilled water in the beaker. Then the addition of 97mL of boiling distilled water is added and stir it well. Then heat it for two minutes and store it in labeled test tube A after cooling. For colloidal solution of egg albumin or milk 1g of milk or egg albumin and 5mL of distilled water is taken in beaker and mixed well. Then the addition of 5ml water is done on stirring. Few drops of dilute hydrochloric acid is added after mixing and then the mixture is stored in labeled test tube B. For transparency we will add a small strip of cellophane paperand paste then on each test tube and observe the colour. The colour spot is seen dim, which means the colloid is translucent. For filtration all the contents in beakers are filtered and observing we see that no residue is seen on the filter paper. So the colloid cannot be separated by filtration. For stability leave the test tube without disturbing it for 25 minutes, we see that no change of solid particle occurs. This means colloidal solutions are stable..