Advertisements
Advertisements
Question
Naphthalene can be separated from sand :
Options
by sublimation
by distillation
by crystallisation
by using water as solvent
Advertisements
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
Match the following
| Column A | Column B | ||
| (a) | Molecules | (i) | Water boils |
| (b) | 100° C | (ii) | Evaporation |
| (c) | 0° C | (iii) | Changes from solid to gas |
| (d) | At all temperatures | (iv) | Matter |
| (e) | Camphor | (v) | Water freezes |
Solids have definite shape and definite volume.
Define the following term of Matter .
Fill in the blank
Liquids have a definite ______
Which of the following substances are elements ?
Water, Salt, Mercury, Iron, Marble, Diamond, Wood, Nitrogen, Air, Graphite, Hydrogen, Oxygen, Sugar, Chlorine
The elements which normally exist in the liquid state are :
How much water should be mixed with 12 mL of alcohol so as to obtain 12 % alcohol solution ?
Choose the correct answer.
A 15% alcohol solution means :
Explain what happens when a beam of light is passed through a colloidal solution.
Which of the following will show Tyndall effect ? Why ?
- Salt solution
- Starch solution
- Milk
- Copper sulphate solution
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 ?
How is the impurity of iron present in several substances removed in industries ?
Describe the various steps involved in the separation of iodine, iron filings and salt from a mixture.
Explain how, impure copper sulphate can be purified by crystallisation.
The best way to recover sugar from an aqueous sugar solution is :
Which one of the following scrap metal cannot be separated by magnetic separation ?
Name one pair of liquids which can be separated by using a separating funnel.
Write a few lines on the blackboard with a chalk. Now observe the chalk. What changes do you see in the chalk?
______ is a smallest particle.
Solid is an arrangement of particles ______.
