Question

When non-metals react with oxygen, _______ are formed.
A. water
B. metal oxides
C. non-metal oxides
D. carbon dioxide

Answer 1

Hint: We know that non-metals are the elements which are electronegative in nature. They can accept electrons to achieve noble gas configuration. Non-metals do not show properties like ductility, malleability, sonorous, lustrous etc. Some non-metals are carbon, sulphur, oxygen etc.

Complete step by step answer:
Now, we understand the oxides of non-metal. The non-metal when reacts with oxygen form non-metal oxides and the oxide formed is acidic in nature.

Sulphur is a non-metal. When sulphur reacts with oxygen, sulphur dioxide forms.

${\rm{S}} + {{\rm{O}}_2} \to {\rm{S}}{{\rm{O}}_{\rm{2}}}$

Now, we have to understand the formed oxide is acidic or basic. On dissolving sulphur dioxide in water, formation of sulphurous acid solution takes place.

${\rm{S}}{{\rm{O}}_{\rm{2}}}\left( g \right) + {{\rm{H}}_{\rm{2}}}{\rm{O}}\left( l \right) \to {{\rm{H}}_2}{\rm{S}}{{\rm{O}}_3}\left( {aq} \right)$


Now, if we place a blue litmus paper to the formed solution, the colour of litmus changes to red. It shows the acidic nature of the oxide.

So, the correct answer is Option C.

Additional information:
Metals also react with oxygen to produce metal oxide and the nature of metal oxide is acidic. Let’s take the example of magnesium.

On reaction of magnesium and oxygen, formation of magnesium oxide takes place.

${\rm{2Mg}} + {{\rm{O}}_{\rm{2}}} \to 2{\rm{MgO}}$

On dissolving non-metals in water, magnesium hydroxide produces.

${\rm{MgO}} + {{\rm{H}}_2}{\rm{O}} \to {\rm{Mg}}\left( {{\rm{O}}{{\rm{H}}_2}} \right)$

When we place a red litmus paper in magnesium hydroxide solution, colour changes to blue. So, the nature of oxide is basic.


Note: some properties of Nonmetals are, they are very soft, bad conductors of electricity, neither malleable nor ductile, non sonorous etc. They do not undergo reaction with acids, they do not react with water also. They react with chlorine to result in covalent chlorides which act as non-electrolytes.