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प्रश्न
Why is white phosphorus kept immersed under water?
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उत्तर
White phosphorus is kept immersed in water because it starts burning spontaneously when it comes into contact with air. But it does not react with water.
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संबंधित प्रश्न
Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Complete and balance the following equation:
Describe the reaction of potassium with water. Write the equation of the reaction involved.
Give one example, with equation, of the displacement of hydrogen by a metal from an acid.
What is the action of water on sodium ? Write equation of the chemical reaction involved.
What is the action of water on magnesium ? Write equation of the chemical reaction involved.
Write the chemical equation of the reaction which takes place when iron reacts with dilute sulphuric acid. What happens when the gas produced is ignited with a burning matchstick?
Write the equation for the reaction of Magnesium with dilute hydrochloric acid.
Name the products formed. Also indicate the physical states of all the substances involved.
Write the equation for the reaction of Iron with dilute hydrochloric acid.
Name the products formed. Also indicate the physical states of all the substances involved.
An acidic oxide is produced by the element:
(a) Na
(b) C
(c) Ca
(d) H
The least reactive metal among the following is:
(a) sodium
(b) silver
(c) copper
(d) lead
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)
Name a metal which It does not react with any physical state of water?
Calcium floats over water during the reaction with water. Give reason.
Arrange the following metals in the increasing order of their reactivities:
Copper, Zinc, Aluminium, and Iron
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iii) Ductility
(iv) High melting point
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
Generally metals react with acids to give salt and hydrogen gas. Which of the following acids does not give hydrogen gas on reacting with metals (except Mn and Mg)?
Metals are generally solid. Which of the following metals is in the liquid state at room temperature?
