Advertisements
Advertisements
Question
Describe a method to separate a mixture of common salt and sand.
Solution
Separation of common salt and sand from a mixture involves the processes of filtration, followed by evaporation.
Sand can be separated from a mixture of sand and salt solution (salt dissolved in water) by filtration. After filtration, sand remains on the filter paper as a residue. Common salt can now be obtained from the filtrate by boiling it. Boiling causes all the water to evaporate and salt is left behind. This process is called evaporation.
APPEARS IN
RELATED QUESTIONS
Gases have definite volume but no definite shape.
Name the processes involved in two cases.
Name the terms for the change of a solid into liquid.
What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain during Brownian motion.
What are the two types of pure substances? Give one example of each type.
What is the other name for impure substances ? Give two examples of impure substances.
Give reason why graphite is used for making elecrode in a dry cell.
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
A solution contains 5.6 mL of alcohol mixed with 75 mL of water. Calculate the concentration of this solution.
Classify the following into true solutions and colloidal solutions:
Ink, Salt solution, Starch solution, Blood, Sugar solution
What is the effect of temperature on the solubility of solids in liquids ?
The solubility of ammonium chloride in water at various temperatures is given below :
| Temperature | : | 10°C | 20°C | 40°C | 60°C | 80°C |
| Solubility | : | 24 g | 37 g | 41 g | 55 g | 66 g |
What mass of ammonium chloride would be needed to make a saturated solution of ammonium chloride in fifty grams of water at 40°C ?
A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?
Explain the meaning of the term matter with special reference to the term ‘substance’.
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 ?
______ is a smallest particle.
Liquids cannot be compressed and they have fixed volume.
Celsius scale is a scale of temperature in which zero represents the melting point of ice and 100 represents the boiling point of water.
Define the term matter.
Define the term matter.
