The vapor pressure of water changes with temperature, as shown here. A student d

Question

The vapor pressure of water changes with temperature, as shown here.

A student designs an ammeter (a device that measures electrical current) that is based on the electrolysis of water into hydrogen and oxygen gases. When electrical current of unknown magnitude is run through the device for 1.50min , 16.3mL of water-saturated H2(g) is collected. The temperature and pressure of the system are 25 ?C and 715 torr.

How many moles of hydrogen gas are produced?

T (?C) P (torr) 21 18.7 22 19.8 23 21.1 24 22.4 25 23.8 26 25.2 27 26.7 28 28.4 29 30.0 30 31.8

Explanation / Answer

Dalton's Law of partial pressures and ideal gas equation can be used.

715 torr = x + 23.8 torr

x = 691.2 torr= pressure of H2

change unit of pressure from torr to atm,1 atm=760 torr

P=691.2 torr/760 torrx1 atm=0.909474 atm

PV = nRT

n=PV/RT=0.909474 atmx0.0163L/298Kx0.08206 L atm / mol K

n=0.000606mol

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.