The density of white tin is 7.28 g cm-3 and the density of gray tin is 4.75 g cm-3. The conversion o — States of Matter Chemistry Question

The density of white tin is 7.28 g cm^-3 and the density of gray tin is 4.75 g cm^-3. The conversion of white tin to gray tin, Sn(s, white) ® Sn(s, gray), has a standard enthalpy of reaction of –2.1 kJ mol^-1 at 298 K. At 1 atm pressure, white tin and gray tin are in equilibrium at 13 °C. Which best represents the phase diagram of tin near 13 °C and 1 atm?