Two different samples of solid iron are shiny, can be made into wire, and can rust when exposed to water. Why do the two samples
1 answer:
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Explanation:
Entropy is defined as the degree of randomness present in a substance. Therefore, more is the irregularity present in a compound more will be its molar entropy.
Hence, decreasing order to molar entropy in state of matter is as follows.
Gases > Liquids > Solids
- In the first pair, we are given
or
. Since, molar entropy of liquids is less than the molar entropy of gases.
Hence, will have larger molar entropy as compared to
.
- In the second pair, we are given Fe(s) or Ni(s). More is the molar mass of a compound more will its molar entropy. Molar mass of Fe is 55.84 g/mol and molar mass of Ni is 58.69 g/mol.
Hence, molar entropy of Ni(s) is more than the molar entropy of Fe(s).
- In the third pair, we are given
or
. As both the given species are gaseous in nature. So, more is the molar mass of specie more will be its molar entropy.
Molar mass of is 30.07 g/mol and molar mass of
is 28.05 g/mol. Therefore, molar entropy of
is more than the molar entropy of
.
- In the fourth pair, we are given
or
. Molar mass of
Therefore, molar entropy of is more than the molar entropy of
.
- In the fifth pair, we are given HgO(s) or MgO(s). Molar mass of HgO is 216.59 g/mol and molar mass of MgO is 40.30 g/mol.
Hence, molar entropy of HgO(s) is more than the molar entropy of MgO.
- In the fifth pair, we are given NaCl(aq) or
. Molar mass of NaCl 58.44 g/mol and molar mass of
Hence, the molar entropy of is more than the molar entropy of NaCl(aq).
Answer: Option (d) is the correct answer.
Explanation:
A reaction in which there occurs change in oxidation state of reacting species is known as an oxidation-reduction reaction.
(a)
Will be written as:
In this reaction, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(b)
Will be written as:
Similarly here, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(c)
Will be written as:
Here, also there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(d)
So, here there occurs change in oxidation state of Mg from 0 to +2 and oxidation state of H changes from +1 to 0. Hence, it is an oxidation-reduction reaction.
Thus, we can conclude that is an oxidation-reduction reaction.