Advertisements
Advertisements
प्रश्न
Which of the following does not have a fixed melting point/boiling point ?
विकल्प
gold
ethanol
air
oxygen
Advertisements
उत्तर
air
Air is a homogeneous mixture of different gases. Hence, it does not have a fixed melting or boiling point.
APPEARS IN
संबंधित प्रश्न
Intermolecular space is maximum in .......... less in ............ and the least in .........
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
Describe in your own words, what happens to the particles when salt dissolves in water.
What is Brownian motion? Draw a diagram to show the movement of a particle (like a pollen grain during Brownian motion.
What is meant by saying that non-metals are brittle ?
What are pure substances ? Give two examples of pure substances.
Classify the following into metals, non-metals and metalloids:
Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium
Which of the following statements are true for pure substances ?
- pure substances contain only one kind of particles
- pure substances may be compounds or mixtures
- pure substances have the same composition throughout
- pure substances can be exemplified by all elements other than nickel
What happens when the temperature of a saturated sugar solution is increased ?
Which of the following will show Tyndall effect ? Why ?
- Salt solution
- Starch solution
- Milk
- Copper sulphate solution
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 is the impurity of iron present in several substances removed in industries ?
How will you separate a mixture of common salt, sulphur powder and sand ?
How is water purified on a large scale at water works ? Explain with the help of a labelled diagram. Name the substance which is added to kill germs in the drinking water supply ?
Which one of the following scrap metal cannot be separated by magnetic separation ?
What difference in the properties of common salt and sand would enable you to separate a mixture of these two substances ?
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 ?
Name the metals that are used in jewellery.
What type of matter glass is?
Solids do not flow.
