Answer to Question #178805 in General Chemistry for Carly Bowman

Question

Given the following information about copper:

 

Specific heat of solid 0.385 J/(g⋅°C)

Specific heat of liquid 0.490 J/(g⋅°C)

Melting point 1086°C

Boiling point 2570°C

Heat of fusion 205 J/g

Heat of vaporization 4799 J/g 

Which quantity of energy is involved in converting 1.50 g of solid copper at 25.0°C to a liquid at 2000.°C?

Answer 1

E₁ = mc∆T

T₁ = 298 K , T₂ = 373 K , $\Delta T$ = 373-298 = 75K

E₁ = 1.50×4.18×75 = 470.25 joules

heat of vaporization E₂ = 1.5 ×4799 joulees = 7198.5 joules

E₃ = mc∆T

T₂ = 373 K, T₃ = 2273K ,∆T = 2273-373 =1900K

E₃ = 1.5×4.18×1900 =11,913joules

Total Energy (E) = E₁ + E₂ + E₃

E = 470.25 + 7198.5 + 11,913

E = 19,581.25 joules