Advertisements
Advertisements
प्रश्न
The important physical properties of substances are colour, odour, nature, density & solubility in water.
Name – a gas with a pungent, choking odour which is lighter than air
Advertisements
उत्तर
A gas with a pungent, choking odour which is lighter than air is Ammonia
संबंधित प्रश्न
Write the Chemical Name of the Following and Also Give Their Molecular Formulae:
Sand
Give two examples of the following.
Non-metals which are lustrous
Indicate whether the following statement is true or false:
Metals reflect light and are good conductors of electricity
Indicate whether the following statement is true or false:
Noble gases are high reactive
Draw a labelled diagram of an atom including its nucleus, orbits & their contents.
Give a reason for the following statement:
Components in a mixture are present in varying proportions and not in a fixed proportion.
Match the separation of components in List I with the most appropriate process in List II.
| List I | List II |
| 1. Naphthalene from naphthalene & sodium chloride. | A: Separating funnel |
| 2. Cream from milk. | B: Sublimation |
| 3. Kerosene oil from kerosene oil & water. | C: Boiling |
| 4. Lead nitrate from an aqueous solution of lead nitrate. | D: Centrifugation |
| 5. Ammonia from an aqueous solution of ammonia. | E: Distillation |
Assertion: Air is a mixture of elements only.
Reason: Only nitrogen, oxygen and neon gases exist in air.
Match the following.
| 1. | Element | Made up of molecules |
| 2. | Compound | Impure substance |
| 3. | Colloid | Settles down on standing |
| 4. | Suspension | Pure substance |
| 5. | Mixture | Made up of atoms |
Oxygen is very essential for us to live. It forms 21% of air by volume. Is it an element or compound?
