EASY
10th CBSE
IMPORTANT
Earn 100

State reasons for the following: Sodium and potassium metals are kept immersed under kerosene oil.

Important Questions on Metals And Non-Metals

EASY
10th CBSE
IMPORTANT
State reasons for the following: Hydrogen gas is not evolved when most metals react with nitric acid.
EASY
10th CBSE
IMPORTANT
Name a metal in each case:
(i) it does not react with cold or hot water, but reacts with steam.
(ii) it does not react with any physical state of water.
EASY
10th CBSE
IMPORTANT
When calcium metal is added 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?
EASY
10th CBSE
IMPORTANT
Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in the reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the gas produced. Write chemical equations for both the reactions.
EASY
10th CBSE
IMPORTANT
When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z, which easily catches fire. Identify X, Y and Z and also write the reaction involved.
EASY
10th CBSE
IMPORTANT
Explain the following: Reactivity of Al decreases if it is dipped in HNO3
EASY
10th CBSE
IMPORTANT
Explain the following: Carbon cannot reduce the oxides of Na or Mg
EASY
10th CBSE
IMPORTANT
Explain the following: NaCl is not a conductor of electricity in the solid state whereas it conducts electricity in the aqueous solution as well as in molten state.