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प्रश्न
Fill in the following blanks with suitable words :
Brass is an alloy which is considered a ..............
उत्तर
Brass is an alloy, which is considered as mixture.
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संबंधित प्रश्न
Differentiate between an atom and a molecule.
All kinds of matter
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
When a crystal of potassium permanganate is placed at the bottom of water in a beaker, the water in the whole beaker turns purple on its own, even without stirring. This is an example of :
Name a metal which is soft and a non-metal which is hard.
What is meant by saying that metals are lustrous ?
The three important metalloids are.............................. and ..........................
Name a metal which is yellow in colour.
Classify the following into elements, compounds and mixtures :
arble, Air, Gold, Brass, Sand, Diamond, Graphite, Petroleum, Common salt, Sea-water, Chalk
One of the following substances is neither a good conductor of electricity nor an insulator. This substance is :
21.5 g of sodium chloride dissolves in 60 g of water at 25°C. Calculate the solubility of sodium chloride in water at that temperature.
What is meant by a solution ? Give two examples of solutions.
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 which can be used to recover salt from an aqueous salt solution.
Describe a method to separate a mixture of camphor and sand.
How will you separate a mixture of common salt, sulphur powder and sand ?
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).
What is fractional distillation ? What is the use of fractionating column in fractional distillation ?
A standard sheet of paper is about ______ of atoms thick
Define the term matter.
