One of the largest diamonds ever found, weighing 0.621 kg, was discovered in South Africa in 1905. The carbon alloptropes graphite and diamond have densities of 2267 and 3515 kg/m3 respectively. At a temperature of 1700K and a pressure of 12.0 x 109 Pascals graphite becomes diamond. Estimate the amount of work that would be needed to form this large diamond from graphite.

Question

the answer is suppose to be 1.17 x10^3 kj
how do i do this question?

Answer 1

using the mass of the diamond
... find the volume of a graphite sphere and a diamond sphere

the pressure compresses the graphite sphere into the diamond sphere
... by pushing on the surface area, through the difference in the radii

the work is an integral function, but you can do a linear approximation

Answer 2

Would it be as easy (or easier) to convert the densities to volume, then use work = p*dV