A phase diagram is a graphical representation of the equilibrium conditions between different phases of a substance, such as solid, liquid, and gas. In this case, we have information about the triple point, critical point, and normal boiling point of the substance.Triple point: 2 atm and 50CCritical point: 70 atm and 400CNormal boiling point: 100C at 1 atm pressure To calculate the boiling point at 1.2 atm pressure, we can use the Clausius-Clapeyron equation, which relates the vapor pressure of a substance at different temperatures. The equation is:ln P2/P1 = Hvap/R * 1/T1 - 1/T2 where P1 and P2 are the vapor pressures at temperatures T1 and T2, Hvap is the enthalpy of vaporization, and R is the ideal gas constant 8.314 J/molK .We know the normal boiling point 100C or 373.15 K and its corresponding pressure 1 atm or 101.325 kPa . We want to find the boiling point at 1.2 atm 121.59 kPa . We can rearrange the equation to solve for T2:1/T2 = 1/T1 - R/Hvap * ln P2/P1 However, we don't have the value for Hvap. A common approximation for substances with similar properties to water is to use Hvap = 40 kJ/mol. This is just an estimation, and the actual value may vary for different substances.Using this approximation, we can plug in the values:1/T2 = 1/373.15 - 8.314/40000 * ln 121.59/101.325 1/T2 0.002681 - 0.000207T2 1/0.002474T2 404.1 KSo, the boiling point at 1.2 atm pressure is approximately 404.1 K or 131C. Keep in mind that this is an estimation based on the approximation for Hvap. The actual boiling point may be different depending on the specific substance and its properties.