Advertisements
Advertisements
प्रश्न
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
Advertisements
उत्तर
(d) Na
Na is soft and can be cut with a knife. It is very reactive and cannot be kept in open air. It reacts vigorously with water.
APPEARS IN
संबंधित प्रश्न
_________ solution is blue in colour.
(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2(SO4)3
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 chemical reaction when iron reacts with dilute H2SO4.
Food cans are coated with tin and not with zinc because ______.
You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
The reaction of an iron nail with copper sulphate solution is ........... reaction.
(a) Combination
(b) Displacement
(c) Double displacement
(d) Decomposition
From amongst the metals sodium, calcium aluminium, copper and magnesium, name the metal:
(i) which reacts with water only on boiling, and
(ii) another which does not react even with steam.
How would you show that silver is chemically less reactive than copper?
Complete and balance the following equation:
Na + O2 →
Fill in the following blank with suitable word:
Magnesium liberates ............... gas on reacting with hot boiling water.
Which of the following elements would yield a basic oxide.
Na, S, C, K, H
What happens when calcium reacts with water? Write the chemical equation of the reaction of calcium with water.
What happens when a metal reacts with dilute hydrochloric acid? Explain with the help of an example.
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.
Zinc oxide is a metal oxide. Which of the following term best describes the nature of zinc oxide:
(a) an acidic oxide
(b) a basic oxide
(c) an amphoteric oxide
(d) a neutral oxide
What is the characteristic of the electronic configuration of noble gases?
Rewrite the following statement by selecting the correct option.
A solution of Al2(SO4)3 in water is _____________.
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
