A gaseous mixture consisting of nitrogen, argon, and oxygen is in a 3.5-L vessel at 25C. Determine the number of moles of oxygen if the total pressure is 98.5kPa and the partial pressure of nitrogen and argon are 22.0kPa and 50.0kPa, respectively.

Number of moles of oxygen = 0.037  mol

Explanation:

Given data:

Total pressure = 98.5 KPa

Partial pressure of nitrogen = 22.0 KPa

Partial pressure of argon = 50.0 KPa

Volume = 3.5 L

Temperature = 25°C (25+273= 298K)

Number of moles of oxygen = ?

Solution:

Total pressure = P(N₂) + P(O₂) + P(Ar)

98.5 KPa = 22.0 KPa +P(O₂) + 50.0 KPa

98.5 KPa = 72.0 KPa +P(O₂)

P(O₂)  = 98.5 KPa - 72.0 KPa

P(O₂)  = 26.5 KPa

KPa to atm:

26.5 KPa/ 101 = 0.262 atm

Number of moles of oxygen:

PV = nRT

n = PV/RT

n = 0.262 atm × 3.5 L / 0.0821 atm.L/mol.K  × 298 K

n = 0.917atm.L /24.47atm.L/ mol

n = 0.037  mol

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.