Question

use the phase diagram of substance x below to find the melting point of x when the pressure above the solid is 1.9 atm. note: your answer must be within 20 °c of the exact answer to be graded correct.

Explanation:

Step1: Locate pressure on graph

Find the pressure value of 19 atm on the pressure - axis of the phase diagram.

Step2: Determine melting - point

The melting - point is the temperature at which the solid - liquid phase boundary intersects the given pressure line. Reading from the phase diagram, when the pressure is 19 atm, the temperature at the solid - liquid boundary is approximately 250 K.

Step3: Convert to Celsius

Use the conversion formula $T(^{\circ}C)=T(K)- 273.15$. So, $T(^{\circ}C)=250 - 273.15=- 23.15^{\circ}C$. Rounding and considering the tolerance of 20°C, we can say the melting - point is around - 23°C.

Answer:

• 23°C