answer the question
Answers
Answer:
1) To prepare pure crystals of potash alum, dissolve the sample in distilled water and remove the insoluble impurities by filtration. This solution is concentrated to the crystallisation point and cooled. Colourless transparant crystals of potash alum separate
2) tyndall effect is the scattering of light by colloidal particles. colloidal solutions and stable suspension solutions show this effect. examples are milk and starch solution.
3) Centrifugation is a technique used for the separation of particles from a solution according to their size, shape, density, viscosity of the medium and rotor speed. The particles are suspended in a liquid medium and placed in a centrifuge tube. The tube is then placed in a rotor and spun at a define speed.
4) Examples of homogeneous mixtures include air, saline solution, most alloys, and bitumen. Examples of heterogeneous mixtures include sand, oil and water, and chicken noodle soup.
5) The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition
6) to Obtain Different Gases from Air. Air can be separated into components by fractional distillation. The below flow diagram shows the steps of the process in the separation of components of air. To separate the oxygen gas present in air, all the other gases present in the air should be separated.
7) In smoke and fog. dispersion medium is same, i.e., air but they differ in dispersed phase. In smoke, solid carbon particles are dispersed in air while in fog, liquid water particles are dispersed in air.
8) Compounds contain two or more different elements. Water is a molecule because it contains molecular bonds. Water is also a compound because it is made from more than one kind of element (oxygen and hydrogen). ... It is not a compound because it is made from atoms of only one element - oxygen.
9) the concentration of 45g salt present in 500g of solution is 9. A solution contains 60g of NaCl in 400g of water
10) Take the combination of salt and napthalene now and place it in the China dish.
Put the mixture in a funnel.
Then place a ball of cotton on top of the funnel.
Now begin the heating of the mixture.
You'll notice some naphthalene ball layer sticking in the funnel.
So, we can easily separate the naphthalene powder.