Which of the following represents a redox reaction? 2 HCl + Na2SO3 ?2NaCl + H2O + SO2 AgNO3 + NaCl ? AgCl + NaNO3 CaCO3 + 2 HBr ? CaBr2 + H2O + CO2 CuS + H2 ? H2S + Cu
The Correct Answer and Explanation is :
The redox reaction among the options is:
CuS + H2 → H2S + Cu
Explanation:
A redox (reduction-oxidation) reaction involves the transfer of electrons between two species, where one species undergoes oxidation (loses electrons), and the other undergoes reduction (gains electrons). In simpler terms:
- Oxidation: Loss of electrons.
- Reduction: Gain of electrons.
Now, let’s break down the reactions and analyze which one is a redox reaction:
- 2 HCl + Na2SO3 → 2 NaCl + H2O + SO2
This is not a redox reaction because there is no change in oxidation states of the elements involved. The sulfur in Na2SO3 remains in the same oxidation state (+4), and the chlorine in HCl also does not undergo a change in its oxidation state. - AgNO3 + NaCl → AgCl + NaNO3
This is an ionic exchange reaction, not a redox reaction. Both silver (Ag) and sodium (Na) remain in their +1 oxidation states throughout the reaction. - CaCO3 + 2 HBr → CaBr2 + H2O + CO2
This is also not a redox reaction. The calcium (Ca) and bromine (Br) do not change oxidation states. The reaction is a simple acid-base reaction with a salt and water formed. - CuS + H2 → H2S + Cu
This is a redox reaction because it involves changes in oxidation states. Copper (Cu) in CuS is in the +2 oxidation state and gets reduced to elemental copper (0). Hydrogen (H2) is oxidized from an oxidation state of 0 to +1 in H2S. Hence, Cu is reduced, and H2 is oxidized.
The correct answer is CuS + H2 → H2S + Cu, as it shows a clear transfer of electrons (reduction and oxidation).
Now, I’ll generate an image illustrating the redox reaction.
Here is an illustration of the redox reaction between copper sulfide (CuS) and hydrogen (H2). It shows how copper is reduced and hydrogen is oxidized in the reaction. Let me know if you need further clarification!