Advertisements
Advertisements
प्रश्न
One of the following does not undergo sublimation. This one is :
विकल्प
camphor
dry ice
silica
iodine
Advertisements
उत्तर
silica
Silica does not sublime on heating.
APPEARS IN
संबंधित प्रश्न
Intermolecular space is maximum in .......... less in ............ and the least in .........
Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
The three important metalloids are.............................. and ..........................
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
What are the three general classes of matter ? Give one example of each type.
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.
Choose the correct answer.
A 15% alcohol solution means :
One of the following does not show Tyndall effect. This one is :
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.
Fill in the following blanks with suitable words :
Immiscible liquids are separated by using a .....................
Which method is better for recovering sugar from sugar solution : evaporation or crystallisation ? Give reason
for your answer.
Naphthalene can be separated from sand :
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 ?
A standard sheet of paper is about ______ of atoms thick
Match the physical quantities given in column A to their S I units given in column B:
| (A) | (B) | ||
| (a) | Pressure | (i) | cubic metre |
| (b) | Temperature | (ii) | kilogram |
| (c) | Density | (iii) | pascal |
| (d) | Mass | (iv) | kelvin |
| (e) | Volume | (v) | kilogram per cubic metre |
The movement of particles in liquids is ______.
Define the term matter.
Define the term matter.
Write a scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
