Question

A jeweler wants to melt a ring. Assume the ring is pure gold and has a mass of 37 grams and the initial temperature of the ring is 55 degrees C. How much energy is required to melt the ring? (Use the attached table for needed constants)

Multiple Choice

A) 7,184.29

B) 2,522.29

C) J 4,853.29 J

D) 2,331 J

special heat capacity (J/kg C) : 130

Melting point (degree C) : 1064

heat of fusion (J/kg) : 134,000

Answer 1

In order to melt the gold ring which is at 55 C temperature .

we need two energy input

first one will increase the temperature of gold ring from 55 to 1064

E1 = m * C * delta_T

E1 = 0.037 * 130 * ( 1064 - 55 )

E1 = 4853.29 J ( this is given as option C but this is not the final answer as gold ring will still be solid at 1064 C )

now we need to calculate the latent heat of fusion which will melt the gold ring while keeping the temperature constant at 1064 C

E2 = m * L

E2 = 0.037 * 134000

E2 = 4958 J

so total energy = E1 + E2

= 4853.29 + 4958

= 9811.29 J

so this is the final answer but none of the options matches with it. you have given either wrong options or wrong data.

feel free to drop comment if you have any doubt. The procedure to calculate the energy is correct.