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प्रश्न
Name the terms for the change of vapour into a liquid.
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उत्तर
Condensation .
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संबंधित प्रश्न
Liquids have definite shape and definite volume.
Name the terms for the change of a solid into liquid.
Which one is a kind of matter:
Describe in your own words, what happens to the particles when salt dissolves in water.
What is meant by saying that non-metals are brittle ?
The three important metalloids are.............................. and ..........................
What are pure substances ? Give two examples of pure substances.
Which of the following are ‘pure substances’ ?
Ice, Milk, Iron, Hydrochloric acid, Calcium oxide, Mercury, Brick, Wood, Air
What is the other name for impure substances ? Give two examples of impure substances.
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.
Out of a colloid, solution and a suspension :
which one has the smallest particles ?
State whether colloidal solutions are homogeneous or heterogeneous.
State whether the following statement is true or false :
Bread is an example of solid foam.
Define Foam Give one example.
100 mL of water at room temperature of 25°C is taken in a beaker and a little of solid S is dissolved in it by stirring to obtain a solution X. More and more of solid S is added to the solution with constant stirring, while keeping the temperature of solution constant at 30°C. After some time it is observed that no more solid dissolves in water and at the same time some solid is also left undissolved at the bottom of the beaker.
- The contents of beaker are filtered through a filter paper to obtain solution Y in the form of a filtrate.
- What name is given to solutions like X ?
- What name is given to solutions like Y ?
- What will you observe if the solution Y at 30°C is cooled down to 10°C by keeping the beaker in crushed ice ? Why ?
- What term is used to denote the amount of solid dissolved in 100 grams of water in a solution lie Y ?
Name the process you would use to separate a mixture of water and alcohol.
Pure copper sulphate can be obtained from an impure sample by the process of :
Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identify the correct set of conditions
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
Define the term matter.
