Question

a solid element (equivalent mass 9) has a specific heat of 1jg_1. calculate atomic mass.​

Answer 1

Answer:

27gm

Explanation:

Given:

 

Specific heat = 1 J/gK

                  = 0.22 cal/g/mol

 

Equivalent weight = 9

 

By using Dulong Petit law,

 

Approximate atomic mass = 6.4 / Specific heat

 

                                      =6.4/ 0.22

 

                                      = 29.09 g

 

Valency = Approximate atomic mass / Equivalent weight

 

           = 29.09 / 9

 

           = 3.23

           =3

 

Exact atomic weight = Equivalent weight × Valency

 

                             = 9× 3

 

                              = 27

 

Exact atomic weight of metal is 27 g.

Answer 2

Answer:

27

Explanation:

according to dulong petit law.,

atomic mass(app.,)Xspecific heat=6.4

• so,atomic mass(app.,)=6.4/specific heat

Given ,1J/g-k

1J/g-k=0.22cal/g/mol

atomic mass(app.,)=6.4/0.22=29.09

Given valency=9

• valency=atomic mass(app.,)/eq.mass

valency=29.09/9=3.23

∴valency=3(app)

accurate atomic mass = eq.massXvalency=9X3=27g