Differentiate between metal and non-metal on the basis of their chemical properties.
Metal | Non-metal |
Metals are electropositive. | Non-metals are electronegative. |
They react with oxygen to form basic oxides. $4 Na + O _{2} \longrightarrow 2 Na _{2} O$ These have ionic bonds. |
They react with oxygen to form acidic or neutral oxides. $C + O _{2} \longrightarrow CO _{2}$ These have covalent bonds. |
They react with water to form oxides and hydroxides. Some metals react with cold water, some with hot water, and some with steam. $2 Na +2 H _{2} O \longrightarrow 2 NaOH + H _{2} \uparrow$ |
They do not react with water. |
They react with dilute acids to form a salt and evolve hydrogen gas. However, $Cu ,\, Ag ,\, Au , \,Pt ,\,Hg$ do not react. $2 Na +2 HCl \longrightarrow 2 NaCl + H _{2} \uparrow$ |
They do not react with dilute acids. These are not capable of replacing hydrogen. |
They react with the salt solution of metals. Depending on their reactivity, displacement reaction can occur. $CuSO _{4}+ Zn \longrightarrow ZnSO _{4}+ Cu$ |
These react with the salt solution of non-metals. |
They act as reducing agents (as they can easily lose electrons). $Na \longrightarrow Na ^{+}+ e ^{-}$ |
These act as oxidising agents (as they can gain electrons). $Cl _{2}+2 e ^{-} \longrightarrow 2 Cl ^{-}$ |
Which of the following methods is suitable for preventing an iron frying pan from rusting ?
Define the following terms.
$(i)$ Mineral $(ii)$ Ore $(iii)$ Gangue
Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.
$(a)$ What will be the action of gas on
$(i)$ dry litmus paper ?
$(ii)$ moist litmus paper ?
$(b)$ Write a balanced chemical equation for the reaction taking place.
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
Metal | Zinc | Magnesium | Copper |
Zinc oxide | - | - | - |
Magnesium oxide | - | - | - |
Copper oxide | - | - | - |
In which cases will you find displacement reactions taking place ?
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.