Question

Calculate the solubility of argon in water at an atmospheric pressure of 0.370 atm (a typical value at high altitude).

Gas Mole Fraction kH mol/(L*atm)
N2 7.81 x 10-1 6.70 x 10-4
O2 2.10 x 10-1 1.30 x 10-3
Ar 9.34 x 10-3 1.40 x 10-3
CO2 3.33 x 10-4 3.50 x 10-2
CH4 2.00 x 10-6 1.40 x 10-3
H2 5.00 x 10-7 7.80 x 10-4

Answer 1

To calculate the solubility of argon in water at 0.370 atm, you apply Henry's Law using the law's constant for argon and the mole fraction of argon in the atmosphere. The formula S = kH × P is used, where S is the solubility, kH is Henry's constant, and P is the partial pressure of argon.

Step-by-step explanation:

The subject of the question is the solubility of argon in water at a specific atmospheric pressure, which is a topic in Chemistry, specifically gas solubility and Henry's Law. To calculate the solubility of argon (Ar) in water at 0.370 atm, we use the given Henry's law constant for argon (kH) and its partial pressure in the atmosphere.

According to Henry's Law, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. The formula to calculate solubility is:

S = kH × P

Where S is the solubility of the gas in the liquid (mol/L),kH is Henry's law constant for the gas (mol/L×atm), and P is the partial pressure of the gas (atm).

For argon, kH is 1.40 x 10-3 mol/L×atm. Since we're given the atmospheric pressure, we need to calculate the partial pressure of argon by multiplying the total pressure by the mole fraction of argon:

Partial pressure of Ar = Total pressure × Mole fraction of Ar = 0.370 atm × 9.34 x 10-3

Now we use the Henry's law equation:

S = (1.40 x 10-3 mol/L×atm) × (0.370 atm × 9.34 x 10-3)

Calculate this value to obtain the solubility of argon in water at 0.370 atm.

Answer 2

4.84 × 10⁻⁶ M

Step-by-step explanation:

First, we will calculate the partial pressure of Ar (pAr) using the following expression.

pAr = P × χAr

where,

P: total pressure

χAr: mole fraction

pAr = P × χAr

pAr = 0.370 atm × 9.34 × 10⁻³

pAr = 3.46 × 10⁻³ atm

We can find the solubility of Ar in water (S) using Henry's law.

S = kH × pAr

where

kH: Henry's constant

S = kH × pAr

S = 1.40 × 10⁻³ M/atm × 3.46 × 10⁻³ atm

S = 4.84 × 10⁻⁶ M