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प्रश्न
Write the chemical equation for the following reaction:
Cinnabar is heated in the presence of air.
उत्तर
\[\ce{\underset{\text{Cinnabar}}{HgS}+\underset{\text{Oxygen from air}}{3O2}->\underset{\text{Mercury(ll) oxide}}{2HgO}+\underset{\text{Sulphur dioxide}}{2SO2}}\]
\[\ce{\underset{\text{Mercury(ii) oxide}}{2HgO}->\underset{\text{Mercury metal}}{2Hg}+\underset{\text{Oxygen gas}}{O2}}\]
In the above reaction when cinnabar is heated in the presence of oxygen, it is reduced to produce pure mercury metal.
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संबंधित प्रश्न
Iron is
(a) More reactive than zinc
(b) More reactive than aluminium
(c) Less reactive than copper
(d) Less reactive than aluminium
What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.
Explain why, the surface of some metals acquires a dull appearance when exposed to air for a long time.
Complete and balance the following equation:
What special name is given to substances like aluminium oxide.
What is meant by the reactivity series of metals? Arrange the following metals in an increasing order of their reactivities towards water:
Zinc, Iron, Magnesium, Sodium
Which of the following reactions will not occur? Why not?
(a) MgSO4 (aq) + Cu (s) → CuSO4 (aq) + Mg (s)
(b) CuSO4 (aq) + Fe (s) → FeSO4 (aq) + Cu (s)
(c) MgSO4 (aq) + Fe (s) → FeSO4 (aq) + Mg (s)
Explain the following:
Reactivity of aluminium decrease if it is dipped in nitric acid.
An element X is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in the air. It reacts vigorously with water. Identify the element from the following.
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
- Good thermal conductivity
- Good electrical conductivity
- Ductility
- High melting point
