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प्रश्न
How would you confirm that a colourless liquid given to your is pure water ?
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उत्तर
You can boil it and if it starts boiling at 100⁰ C, it might be water. You can also check its reactivity with some metals such as sodium and potassium that react violently with water. The best way, to prove that it is pure water, is to do experiments to see if it has the same capabilities and chemical behaviour as water has.
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संबंधित प्रश्न
Gases have definite volume but no definite shape.
Which one is a kind of matter:
Which of the following are not compounds ?
Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond
What are the three general classes of matter ? Give one example of each type.
Define solubility of a substance. How does it vary with temperature ?
What is a suspension ? Give two examples of suspensions.
Milk of Magnesia is :
What is the difference between colloids and suspensions ?
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.
Describe a method to separate a mixture of common salt and sand.
How will you separate a mixture of iron filings, chalk powder and common salt ?
Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.
The correct increasing order of the boiling points of liquid oxygen, liquid argon and liquid nitrogen present in liquid air is :
Select the correct answer from A, B, C, D & E for the statement given below:
An atom or group of atoms _________ having a resultant charge.
Diffentiate between absorption and adsorption.
Which among the following is not a matter?
Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compounds or mixtures
(iii) Pure substances have the same composition throughout
(iv) Pure substances can be exemplified by all elements other than nickel
Solids do not flow.
Boiling refers to the process by which a substance changes from the liquid to the gaseous state at its ______ point.
Define the term matter.
