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प्रश्न
What is chromatography ? State its two applications.
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उत्तर
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.
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संबंधित प्रश्न
Match the following
| Column A | Column B | ||
| (a) | Molecules | (i) | Water boils |
| (b) | 100° C | (ii) | Evaporation |
| (c) | 0° C | (iii) | Changes from solid to gas |
| (d) | At all temperatures | (iv) | Matter |
| (e) | Camphor | (v) | Water freezes |
Liquids have definite volume but do not have definite shape.
Gases have definite volume but no definite shape.
Name the property which enables metals to be drawn into wires.
Which type of elements, metals or non-metals, show the property of brittleness ?
What is meant by saying that non-metals are brittle ?
What elements do the following compounds contain ?
Sugar, Common salt
State any two properties for believing that aluminium is a metal.
Name a metal which forms amalgams.
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
- What type of substance could X be ? Name one substance like X.
- What type of substance could Y be ? Name one substance like Y.
- What type of substance could Z be ? Name one substance like Z.
- Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
- Name the three groups into which all the substances like Y are divided on the basis of their properties.
Which of the following is a sol ?
Shaving cream, Milk, Fog, Soap solution, Hairspray
Explain what happens when a beam of light is passed through a colloidal solution.
Name the different types of solutions. Give one example of each.
How will you separate a mixture of iron filings, chalk powder and common salt ?
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
What's the solution?
We need to make a sherbet quickly for some guests. But we only have sugar candy in the house.
______ is not made of matter.
State whether true or false. If false, correct the statement.
Oil and water are immiscible with each other.
Liquids have ______.
Gas-solid is ______.
