Question

Arsine, AsH3, is a highly toxic compound used in the electronics industry for the production of semiconductors. Its vapor pressure is 35 Torr at 111.95 C and 253 Torr at 83.6 C. Using these data, calculate (a) the standard enthalpy of vaporization;

Answer 1

-79.8 × 10⁴ J/mol

Step-by-step explanation:

Arsine, AsH₃, is a highly toxic compound used in the electronics industry for the production of semiconductors. Its vapor pressure is 35 Torr at 111.95 °C and 253 Torr at 83.6 °C.

Then,

P₁ = 35 torr

T₁ = 111.95 + 273.15 = 385.10 K

P₂ = 253 torr

T₂ = 83.6 + 273.15 = 356.8 K

We can calculate the standard enthalpy of vaporization (ΔH°vap) using the two-point Clausius-Clapeyron equation.

`ln((P_(2))/(P_(1)) )=(-\Delta H\°_(vap))/(R) .((1)/(T_(2)) -(1)/(T_(1)) )`

where,

R is the ideal gas constant

`ln((253torr)/(35torr))=(-\Delta H\°_(vap))/(8.314J/K.mol) .((1)/(356.8K)-(1)/(385.10K))\\ \Delta H\°_(vap)=-79.8 * 10^(4) J/mol`