8. State Dalton\'s law of partial pressures. (2 pts) 9. A sample of carbon monox

Question

8. State Dalton's law of partial pressures. (2 pts) 9. A sample of carbon monoxide was collected over water at a total pressure of 766 torr and a temperature of 18°C·What is the pressure of the carbon monoxide? The vapor pressure of water at 18C is 15.5 torr. (3 pts) 10. In an experiment in a general chemistry laboratory, a student collected a sample of a gas over water. The volume of the gas was 125 mL at a pressure of 766 torr and a temperature of 27 °C. The mass of the gas was 0.472 g. What was the molar mass of the gas? (4 pts)

Explanation / Answer

Q8.

Dalton states that

The sum of ALL parital pressure of a gas, will yield the TOTAL pressure of the gas mixture

therefore

Ptotal = P1 + P2 + P3 .... Pn, sum up to "n" gases

Q9

Apply dalton partial pressure law

Ptotal = Pgas + Pvapor

766 torr = Pgas + 15.5 torr

Pgas = 766-15.5

Pgas = 750.5 torr

Q10

Pgas = Ptotal - Pvapor (27°C) = 766-26.7 = 739.3

PV = nRT

n = PV/(RT) = (739.3)(0.125)/(62.4*300)

n = 0.00493 moles of gas

MM = mass / mol

MM = 0.472/0.00493

MM = 95.740 g/mol

Related Questions

Navigate

• Browse (All)
• Browse 8
• Subjects

---

---

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