✓ Board-verified↻ asked 2×
Science · 2023 · 4 marks
CBSE 2023 · Region 1 · Set 2 · Q39
Almost all metals combine with oxygen to form metal oxides. Metal oxides are generally basic in nature. But some metal oxides show both basic as well as acidic behaviour. Different metals show different reactivities towards oxygen. Some react vigorously while some do not react at all.(a)What happens when copper is heated in air ? (Give the equation of the reaction involved).(b)Why are some metal oxides categorized as amphoteric ? Give one example.Complete the following equations :(i)$\displaystyle \mathrm{Na}_{2} \mathrm{O}_{(\mathrm{s})}+\mathrm{H}_{2} \mathrm{O}_{(l)} \rightarrow$(ii)$\displaystyle \mathrm{Al}_{2} \mathrm{O}_{3}+2 \mathrm{NaOH} \rightarrow$On burning Sulphur in oxygen a colourless gas is produced.(i)Write chemical equation for the reaction.(ii)Name the gas formed.(iii)State the nature of the gas.(iv)What will be the action of this on a dry litmus paper ?
Almost all metals combine with oxygen to form metal oxides. Metal oxides are generally basic in nature. But some metal oxides show both basic as well as acidic behaviour. Different metals show different reactivities towards oxygen. Some react vigorously while some do not react at all.
(a)
What happens when copper is heated in air ? (Give the equation of the reaction involved).
(b)
Why are some metal oxides categorized as amphoteric ? Give one example.
Complete the following equations :
(i)
$\displaystyle \mathrm{Na}_{2} \mathrm{O}_{(\mathrm{s})}+\mathrm{H}_{2} \mathrm{O}_{(l)} \rightarrow$
(ii)
$\displaystyle \mathrm{Al}_{2} \mathrm{O}_{3}+2 \mathrm{NaOH} \rightarrow$
On burning Sulphur in oxygen a colourless gas is produced.
(i)
Write chemical equation for the reaction.
(ii)
Name the gas formed.
(iii)
State the nature of the gas.
(iv)
What will be the action of this on a dry litmus paper ?
Marking-scheme solution
(a)
\(\displaystyle 2 \mathrm{Cu}+\mathrm{O}_{2} \longrightarrow 2 \mathrm{CuO}\)
(b) • Because they react with both acids and bases to produce salt and water.
\(\displaystyle \mathrm{Al}_{2} \mathrm{O}_{3 /} \mathrm{ZnO}\)
(c) (i) \(\displaystyle \mathrm{Na}_{2} \mathrm{O}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \longrightarrow 2 \mathrm{NaOH}(\mathrm{aq})\)
(ii) \(\displaystyle \mathrm{Al}_{2} \mathrm{O}_{3}+2 \mathrm{NaOH} \longrightarrow 2 \mathrm{NaAlO}_{2}+\mathrm{H}_{2} \mathrm{O}\)
(c) (i) \(\displaystyle \mathrm{S}+\mathrm{O}_{2} \longrightarrow \mathrm{SO}_{2}\)
(ii) Sulphur dioxide
(iii) Acidic
(iv) No change
More from Metals and Non-metals
- A metal, M, displaces iron from aqueous solution of ferrous sulphate but fails to do so in case of aqueous…2025 · asked 3×
- List two advantages of adopting the atomic number of an element as the basis of classification of elements in…2022 · asked 3×
- Attempt either or: (i) Write one example each of one metal that is so soft that it can be cut with a knife,…2026 · asked 3×
- The melting points and boiling points of some ionic compounds are given below: These compounds are termed…2023 · asked 3×
- Two metals zinc and tin are dissolved separately in definite proportions in molten copper (the primary metal)…2025 · asked 3×
- The metals produced by various reduction processes are not very pure. They contain impurities, which must be…2024 · asked 3×
- Read the following passage and answer the questions given below: Most of metals occur in combined state in…2026 · asked 3×
- The pH plays an important role in our daily life. Strength of acids and bases depends on the number of H^+…2026 · asked 3×
CBSE Class 10 Science past-paper question from the 2023board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.