Choose the correctly matched pair.a)Burning of coal - C(s) + O2(g) &ra...
- Let's analyze each option to determine the correctly matched pair:
- Option A: (a) Burning of coal - C(s) + O2(g) → CO2(g)
- This is a correct chemical equation for the burning of coal, which is a combination reaction. However, let's verify the other options before concluding.
- Option B: (b) Formation of water - 2H2(g) + O2(g) → 2H2O(l)
- This is also a correct chemical equation for the formation of water from hydrogen and oxygen, which is another example of a combination reaction. We need to check the remaining options as well.
- Option C: (c) Respiration - C6H12O6(aq) + 6O2(aq) → 6CO2(aq) + 6H2O(l) + energy
- This equation correctly represents the process of respiration, an exothermic reaction where glucose reacts with oxygen to produce carbon dioxide, water, and energy.
- Option D: (d) Whitewashing reaction - Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)
- This is the correct chemical equation for the whitewashing reaction. When calcium hydroxide reacts with carbon dioxide, it forms calcium carbonate (which gives a shiny finish on walls) and water.
- All options are correctly matched pairs, but the question asks for one correctly matched pair. Therefore, Option D is chosen as it represents a familiar and specific application that students are likely to recognize easily.
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Choose the correctly matched pair.a)Burning of coal - C(s) + O2(g) &ra...
As in 1st option CO is formed in place of CO2 it is wrong
in 2nd option it is not a balanced reaction as well as H2O should be formed
in 3rd option CO2 AND H2O is formed
therefore 4th is correct
Choose the correctly matched pair.a)Burning of coal - C(s) + O2(g) &ra...
Whitewashing reaction
The correct reaction for whitewashing is:
Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)
Explanation
- Whitewashing: Whitewashing is a process of applying a mixture of lime and water to walls to give them a white finish.
- Calcium hydroxide: Ca(OH)2, also known as slaked lime, is a key component in whitewashing mixtures.
- Carbon dioxide: When carbon dioxide (CO2) from the air reacts with calcium hydroxide, it forms calcium carbonate (CaCO3) and water (H2O).
- Chemical reaction: The chemical equation for the whitewashing reaction shows the formation of solid calcium carbonate and liquid water as products.
- Importance: Whitewashing not only provides a visually appealing finish but also helps in protecting the walls from weathering and enhances the durability of the surface.
By following this reaction, whitewashing can be effectively performed to give walls a fresh and clean appearance.