Question #b7786

2 Answers
Aug 30, 2017

Answer:

#600 cm^3#

Explanation:

for the Dalton law about partial pressure you must take off from the first conditions the vapour pressure of water (380 torr = 0,5 atm) and remains 1,5 atm. Now with the ideal gasses law (or with Boyle's law) you can change the conditions:
#P_1 xx V_1 = P_2 xx V_2#
Where STP are normally 1 atm.
#V_2 = P_1 xx V_1 / P_2= (1,5atm xx 400 cm^3) /(1atm) = 600 cm^3#

Aug 31, 2017

Answer:

#787,6 cm^3#

Explanation:

for the Dalton law about partial pressure you must take off from the first conditions the vapour pressure of water (the saturated vapour pressure of water at 25°C that is 23,8 mmHg = 0,031 atm)
iand remains 1,969 atm. Now with the ideal gasses law (or with Boyle's law) you can change the conditions:
#P_1 xx V_1 = P_2 xx V_2#
Where STP are normally 1 atm
#V_2 = (V_1 xx P_1)/(P_2) = (400 cm^3 xx 1,969 atm)/(1 atm)= 787,6 cm^3#
i hope this time it's right