Advertisements
Advertisements
प्रश्न
Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
- What type of substance is B ?
- What type of substance is C ?
- Name the gas (i) D, and (ii) E ?
- State one characteristic property of gas D.
- Write one test to identify gas E.
Advertisements
उत्तर
- Here, iron powder and sulphur powder are mixed together. B is a mixture (Fe + S).
- Here, iron powder and sulphur powder are mixed together and heated strongly on a burner. So, C is the compound iron sulphide(FeS).
- i. Here, dilute HCl was added to C (iron sulphide)to obtain D, which is hydrogen sulphide gas.
FeS + 2HCl → FeCl2 + H2S
ii. When dilute HCl is added to B, Fe present in the mixture reacts with the acid to form hydrogen gas.
Fe + HCl → FeCl2 + H2 - Gas D smells like rotten egg.
- When a burning stick is held in the gas, the gas itself catches fire with blue flame and a ‘pop’ sound. In the process, the burning stick extinguishes.
APPEARS IN
संबंधित प्रश्न
Intermolecular space is maximum in .......... less in ............ and the least in .........
Explain why air is used to inflate tyres.
What are the characteristics of matter?
Name a non-metal which is a good conductor of electricity.
Name a non-metal :
- which is lustrous
- which is required for combustion
- whose one of the allotrophic forms is a good conductor of electricity. Name the allotrope.
- other than carbon which shows allotropy
- which is known to form the largest number of compounds
What are (i) metals (ii) non-metals, and (iii) metalloids ? Give two examples each of metals, non-metals and metalloids.
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
Define solvent.
How will you test whether a given solution is a colloidal solution ?
What is the effect of temperature on the solubility of solids in liquids ?
Tincture of iodine has antiseptic properties. This solution is made by dissolving :
How will you separate a mixture of common salt, sulphur powder and sand ?
The dyes present in fountain pen ink can be separated by the technique of :
Explain the meaning of the term ‘matter’.
______ is a smallest particle.
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
You want to wear your favourite shirt to a party, but the problem is that it is still wet after a wash. What steps would you take to dry it faster?
Gases do not diffuse very easily.
______ is used for industrial refrigeration and transporting frozen food.
The fluidity of solids: ______.
