Answer
Verified
396k+ views
Hint: We can define enthalpy of fusion as the heat evolved in the reaction when an element changes its state from one state to another. The units for this are (KJ/mol), or sometimes (J/g) units are also used.
Complete answer:
- We can see that if there is any element ${{A}_{\left( s \right)}}$ and we are changing it in liquid state ${{A}_{\left( l \right)}}$ at constant pressure, then the heat will be evolved in this reaction, and we call this heat evolved as enthalpy of fusion, which is denoted by${{\Delta }_{r}}H$.
${{A}_{\left( s \right)}}\to {{A}_{\left( l \right)}}$
- So, if we convert it from solid to liquid state, we have to apply heat because as we know that solid is present in a very compact form, and we supply heat constantly.
- We know that solid is having compact arrangement of atoms, for example in case of KCl , ${{K}^{+}}$ and \[C{{l}^{-}}\]are very strongly bonded to each other because the electronegativity difference in both of these is high.
- So, KCl is very compact molecule, and if we about compactness or rigidity in KCl or naphthalene,
That is if see whether which one is more rigid than other, then it is found that KCl > naphthalene, because ${{K}^{+}}$ and \[C{{l}^{-}}\] are bonded and are compact as compared to naphthalene.
- The energy which we will provide to KCl in order to dissociate or we can say to change its state from solid to liquid, as compared to energy provided to naphthalene will be more.
- We are giving $\Delta {{H}_{1}}$ heat in KCl and $\Delta {{H}_{2}}$ in naphthalene, so it is clear that we have to give more heat in KCl because we need more heat in order to break bond in KCl
- Hence, we can say that $\Delta {{H}_{1}}$>$\Delta {{H}_{2}}$
Now, we can conclude that the option (c) is correct that is, the relation between the enthalpy of fusion of KCl and naphthalene is KCl >naphthalene.
Note:
- We can say that the stronger the bond present or greater difference in electronegativity between two atoms, more heat energy will be required to break the bond and such molecules will have high enthalpy of fusion.
Complete answer:
- We can see that if there is any element ${{A}_{\left( s \right)}}$ and we are changing it in liquid state ${{A}_{\left( l \right)}}$ at constant pressure, then the heat will be evolved in this reaction, and we call this heat evolved as enthalpy of fusion, which is denoted by${{\Delta }_{r}}H$.
${{A}_{\left( s \right)}}\to {{A}_{\left( l \right)}}$
- So, if we convert it from solid to liquid state, we have to apply heat because as we know that solid is present in a very compact form, and we supply heat constantly.
- We know that solid is having compact arrangement of atoms, for example in case of KCl , ${{K}^{+}}$ and \[C{{l}^{-}}\]are very strongly bonded to each other because the electronegativity difference in both of these is high.
- So, KCl is very compact molecule, and if we about compactness or rigidity in KCl or naphthalene,
That is if see whether which one is more rigid than other, then it is found that KCl > naphthalene, because ${{K}^{+}}$ and \[C{{l}^{-}}\] are bonded and are compact as compared to naphthalene.
- The energy which we will provide to KCl in order to dissociate or we can say to change its state from solid to liquid, as compared to energy provided to naphthalene will be more.
- We are giving $\Delta {{H}_{1}}$ heat in KCl and $\Delta {{H}_{2}}$ in naphthalene, so it is clear that we have to give more heat in KCl because we need more heat in order to break bond in KCl
- Hence, we can say that $\Delta {{H}_{1}}$>$\Delta {{H}_{2}}$
Now, we can conclude that the option (c) is correct that is, the relation between the enthalpy of fusion of KCl and naphthalene is KCl >naphthalene.
Note:
- We can say that the stronger the bond present or greater difference in electronegativity between two atoms, more heat energy will be required to break the bond and such molecules will have high enthalpy of fusion.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
How do you arrange NH4 + BF3 H2O C2H2 in increasing class 11 chemistry CBSE
Is H mCT and q mCT the same thing If so which is more class 11 chemistry CBSE
Trending doubts
State the differences between manure and fertilize class 8 biology CBSE
Why are xylem and phloem called complex tissues aBoth class 11 biology CBSE
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Difference Between Plant Cell and Animal Cell
What would happen if plasma membrane ruptures or breaks class 11 biology CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
What precautions do you take while observing the nucleus class 11 biology CBSE
What would happen to the life of a cell if there was class 11 biology CBSE
Change the following sentences into negative and interrogative class 10 english CBSE