At which temperature will water boil when the external pressure is 17.5 torr

1) 14.5 ° C
2) 16.5 ° C
3) 20 ° C
4) 100 ° C

Thank you!

use this equation...
ln(P1 / P2) = (dHvap / R) x (1/T2 - 1/T1)

the idea is we have 2 paired (P,T) points
P1 = 1atm
T1 = 100°C = 373.15K
P2 = 17.5torr = 17.5torr x (1atm/760torr) = __ atm
T2 = ?.. the unknown
dHvap = heat of vaporization of water = 40680 J/mole
R = gas constant = 8.314 J/moleK

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can you finish?