Practice problem, answer is given but I need steps to get to solution. Thank you!

Carbon dioxide (CP 38 J/mol-K) at 1.5 MPa and 25C is expanded to 0.1 MPa through a throttle valve. Determine the temperature of the expanded gas. Work the problem using a CO2 chart, noting that the triple point of CO2 is at 56.6C and 5.2 bar, and has a heat of fusion, H fus, of 43.2 cal/g. (ANS. 194 K, sat S V)