Advertisements
Advertisements
Question
Naphthalene can be separated from sand :
Options
by sublimation
by distillation
by crystallisation
by using water as solvent
Solution
by sublimation
Naphthalene sublimes on heating, whereas sand does not. So, when the mixture is heated, solid naphthalene turns into vapours, which can be condensed. Sand remains in the container.
APPEARS IN
RELATED QUESTIONS
Which of the following materials fall in the category of a “pure substance”?
- Ice
- Milk
- Iron
- Hydrochloric Acid
- Calcium oxide
- Mercury
- Brick
- Wood
- Air
When a gas jar containing air is inverted over a gas jar containing bromine vapour, the red-brown bromine vapour diffuse into air. Explain how bromine vapour diffuse into air.
Define matter. Give four examples of matter.
What name is given to those elements which are neither good conductors of electricity like copper nor insulators like sulphur ?
What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.
Calculate the concentration of a solution which contains 2.5 g of salt dissolved in 50 g of water.
Which of the following do not exhibit Tyndall effect ?
Starch solution, Sugar solution, Ink, Salt solution, Copper sulphate solution, Ammonium chloride solution, Fog, Smoke, Car exhausts.
How would you prepare a saturated solution of sodium chloride in water at 25°C ? What will happen if this solution is cooled to 10°C ?
Tincture of iodine has antiseptic properties. This solution is made by dissolving :
State whether the following statement are true or false :
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.
Name the process which is used in milk dairies to separate cream from milk.
Name the process by which common salt is purified.
Fill in the following blanks with suitable words :
Immiscible liquids are separated by using a .....................
A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with
cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the
process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And
S is a white solid which is used in making ordinary dry cells.
- What could P, Q, R and S be ?
- How would you separate a mixture containing P, Q, R and S ?
Wipe the board with a duster and then tap the duster against the table. What do you see?
Name the metals that are used in jewellery.
Gases do not diffuse very easily.
______ is used for industrial refrigeration and transporting frozen food.
Define the term matter.
