Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Sodium is more reactive than calcium. The reaction between sodium and water produces a large amount of heat, which causes the evolved hydrogen to burn and catch fire. But in the reaction between calcium and water, no heat is produced and hence the evolved hydrogen does not catch fire.
APPEARS IN
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.
What will happen if a strip of copper is kept immersed in a solution of silver nitrate (AgNO3)?
Explain why, the surface of some metals acquires a dull appearance when exposed to air for a long time.
Which of the following elements would yield an acidic oxide.
Na, S, C, K, H
Which of the following elements would yield a basic oxide.
Na, S, C, K, H
Name two metals which cannot displace hydrogen from dilute acids.
Write one reaction in which aluminium oxide behaves as a basic oxide and another in which it behaves as an acidic oxide.
Name another metal oxide which behaves like aluminium oxide.
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?
An acidic oxide is produced by the element:
(a) Na
(b) C
(c) Ca
(d) H
You are given a solution of AgNO3. Which of the following do you think cannot displace Ag from AgNO3solution?
(a) Magnesium
(b) Zinc
(c) Gold
(d) Copper
A metal less reactive and another metal more reactive than hydrogen are:
(a) aluminium and lead
(b) iron and magnesium
(c) copper and tin
(d) copper and mercury
Which one of the following four metals would be displaced from the solution of its salt by the other three metals?
(a) Zn
(b) Ag
(c) Cu
(d) Mg
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?
What is the cause of chemical bonding (or chemical combination) of atoms of elements?
Write the chemical equation for the following reaction:
Calcium metal reacts with water.
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
Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?
Tungsten wire is used in electric bulbs.
