Advertisements
Advertisements
प्रश्न
Fill in the following blanks with suitable words :
The separation of liquids by fractional distillation is based on the difference in their .....................
Advertisements
उत्तर
The separation of liquids by fractional distillation is based on the difference in their boiling points.
APPEARS IN
संबंधित प्रश्न
The molecules can move freely anywhere in
Define matter.
State two characteristics of matter demonstrated by Brownian motion.
Bromine and air take about 15 minutes to diffuse completely but bromine diffuses into a vacuum very rapidly. Why is this so?
What are the three groups into which all the elements can be divided ? Name two elements belonging to each group.
State two physical properties on the basis of which metals can be distinguished from non-metals.
Classify the following into metals, non-metals and metalloids:
Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium
State whether colloidal solutions are homogeneous or heterogeneous.
Choose the correct answer.
A 15% alcohol solution means :
Define Foam Give one example.
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 source from which nitrogen and oxygen are obtained on a large scale.
A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose ?
How will you separate camphor, common salt and iron nails from their mixture ?
Which of the following statements are true for pure substances?
(i) Pure substances contain only one kind of particles
(ii) Pure substances may be compounds or mixtures
(iii) Pure substances have the same composition throughout
(iv) Pure substances can be exemplified by all elements other than nickel
The movement of particles in liquids is ______.
Solids do not flow.
Evaporation is always accompanied by ______ in temperature.
Give an example of a molecule.
Define the term matter.
