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प्रश्न
Which technique can be used to detect and identify traces of poison present in the stomach wash of a person ?
उत्तर
Chromatography is a technique that can be used to detect and identify traces of poison in the stomach of a person.
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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 |
Fill in the blank :
The state of matter with definite volume and definite shape is called______
What are the conditions for 'something' to be called 'matter'?
Define matter. Give four examples of matter.
In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?
Name a metal which is soft and a non-metal which is hard.
Give reason why graphite is used for making elecrode in a dry cell.
Name a metal which has no fixed shape.
Explain what happens when a beam of light is passed through a colloidal solution.
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.
Name the process you would use to separate a mixture of water and alcohol.
What difference in the properties of oil and water enable their separation by a separating funnel ?
Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.
With the help of a labelled diagram, describe the method of separating ammonium chloride from a mixture of ammonium chloride and common salt. Mention the difference in the properties of ammonium chloride and sodium chloride which has made this separation possible.
How can you obtain pure water from a salt-water mixture (or salt-solution) ? Draw a neat and labelled diagram of the apparatus you would use to obtain pure water from a salt-water mixture (or salt-solution).
If there is a sudden shower, we take shelter under a roof at the roadside. Even though the rain does not fall on us directly, we get wet to some extent. Why ?
Justify your answer.
| Figure 1 | Figure 2 | Figure 3 |
 |
 |
 |
The arrangement of particles in three different phases of matter is shown above.
- Which state is represented by Fig. 1?
- In which state will the inter-particle attraction be maximum?
- Which one of them cannot be contained in an open vessel?
- Which one can take the shape of its container?
Higher the temperature, the higher the kinetic energy of particles.
Define the term matter.
