Advertisements
Advertisements
Question
What is chromatography ? State its two applications.
Solution
Chromatography is a technique used for separating two or more dissolved solids, which are present in the solution in small quantities.
Separation is based on the fact that two or more substances are soluble in the solvent but their solubility is different.
This technique has various important applications:
- To separate dyes present in black ink
- It is used in forensic science to detect and identify the trace amounts of poison present in the stomach.
APPEARS IN
RELATED QUESTIONS
Intermolecular force of attraction is maximum in ............ less in .......... and the least in .............
What are the two conditions for the interconversion of states of matter ?
When extremely small particles X derived from the anther of a flower were suspended in a liquid Y and observed through a microscope, it was found that the particles X were moving throughout the liquid Y in a very zig-zag way. It was also observed that warmer the liquid Y, faster the particles X moved on its surface.
- What could particles X be ?
- What do you think liquid Y is ?
- What is the zig-zag movement of X known as ?
- What is causing the zig-zag movement of particles X ?
- Name the scientist who discovered this phenomenon.
- What does this experiment tell us about the nature of liquid Y?
Classify the following into elements and compounds :
- H2O
- He
- Cl2
- CO
- Co
Name a metal which is yellow in colour.
In the following set of substances, one item does not belong to the set. Select this item and explain why it does not belong to the set :
Hydrogen, Oxygen, Steam, Chlorine
There is a large group of materials P which can be divided into three groups Q, R and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.
- What could the group of materials P be ?
- Name the substances Q. Give two examples of such substances.
- Name the substances R. Write two examples of such substances.
- Name the substances S. Give two examples of such substances.
- Out of Q, R and S, which substances are malleable and ductile ?
Choose one term from the following which includes the other three :
aerosol, emulsion, colloid, sol
Fill in the following blank :
A colloid is a ..............mixture and its components can be separated by the technique known as ...............
When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.
(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A. Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.
What difference in the property of two miscible liquids enables their separation by fractional distillation ?
Name the process which can be used to purify an impure sample of copper sulphate.
How is the impurity of iron present in several substances removed in industries ?
One of the following does not undergo sublimation. This one is :
Explain the meaning of the term matter with special reference to the term ‘substance’.
Write a scientific reason.
Lemon sherbat has a sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
Define the term matter.
Define the term matter.
