How much energy is needed to melt 161.0 g of ethanol(C₂H₅OH)?(Heat of fusion Ethanol- 5.02 KJ/mol)

17.6kJ

Explanation:

The mass of ethanol given is 161.g

 Now we first find the number of moles from this.

 Number of moles  =

            Molar mass of C₂H₅OH = 2(12) + 5(1) + 16 + 1  = 46g/mol

Number of moles of ethanol  =   = 3.5mol

Since the heat of fusion is  5.02kJ/mol;

       Heat of fusion is a measure of the amount of energy needed to melt a substance.

  Amount of energy needed to melt =  3.5mol x  5.02kJ/mol

                                                             = 17.6kJ

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."