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प्रश्न
How do metals react with hydrogen? Explain with an example.
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उत्तर
Metals generally do not react with hydrogen. But some reactive metals like sodium, potassium, calcium, and magnesium can force the hydrogen atom to accept electrons from them and form salt-like ionic solid compounds called metal hydrides.
When hydrogen gas is passed over heated sodium, then sodium hydride is formed.
\[\ce{\underset{(A metal)}{\underset{Sodium}{2Na_{(s)}}} + \underset{Hydrogen}{H2_{(g)}} -> \underset{(Ionic hydride)}{\underset{Sodium hydride}{2NaH_{(s)}}}}\]
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संबंधित प्रश्न
Metal A has electronic configuration (2, 8, 1) and metal B has (2, 8, 8, 2). Which is more reactive? Why? Identify these metals.
Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
| Metal | Iron (II) sulphate | Cooper (II) sulphate | Zinc sulphate | Silver nitrate |
| A | No reaction | Displacement | ||
| B | Displacement | No reaction | ||
| C | No reaction | No reaction | No reaction | Displacement |
| D | No reaction | No reaction | No reaction | No reaction |
Use the Table above to answer the following questions about metals A, B, C and D.
- Which is the most reactive metal?
- What would you observe if B is added to a solution of copper (II) sulphate?
- Arrange the metals A, B, C and D in the order of decreasing reactivity.
Write the electron-dot structures for sodium, oxygen and magnesium.
Complete and balance the following equation:
\[\ce{Na2O + H2O ->}\]
Ordinary aluminium strips are not attacked by water because of the presence of a layer of ______ on the surface of aluminium.
What is the nature of the oxide Na2O? What happens when it is dissolved in water? Write the chemical equation of the reaction involved.
Give one example, with equation, of the displacement of hydrogen by a metal from an acid.
Write the equation for the reaction of Aluminium 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 Zinc with dilute hydrochloric acid.
Name the products formed. Also indicate the physical states of all the substances involved.
Name one metal which displaces silver from silver nitrate solution and one which does not.
Out of aluminium, copper, calcium and tin, the most reactive metal is:
(a) aluminium
(b) copper
(c) tin
(d) calcium
The elements whose oxides can turn litmus solution red are:
(a) lithium and sodium
(b) copper and potassium
(c) carbon and hydrogen
(d) phosphorus and sulphur
An element is soft and can be cut with a knife. If is very reactive and cannot be kept open in the air. It reacts vigorously with water. The element is most likely to be:
(a) Mg
(b) S
(c) P
(d) Na
If A, B, C, D, E, F, G, H, I, J and K represent metals in the decreasing order of their reactivity, which one of them is most likely to occur in a free state in nature?
When calcium metal is added to water, the gas evolved does not catch fire but the same gas evolved on adding sodium metal to water catches fire. Why is it so?
Write a chemical equation to illustrate the use of aluminium for joining cracked railway lines.
Answer the following question:
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is metal or a non - metal. Explain with a proper example.
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
A cable manufacturing unit tested few elements on the basisof their physical properties.
| Properties | W | X | Y | Z |
| Malleable | Yes | No | No | Yes |
| Ductile | Yes | No | No | Yes |
| Electrical conductivity | Yes | Yes | Yes | No |
| Melting Point | High | Low | Low | High |
Which of the above elements were dicarded for usage by the company?
