In water, which of the following gases has the highest Henry's law constant at 293 K?

CONCEPT:

Henry's Law Constant

• Henry's Law states that the amount of gas dissolved in a liquid is directly proportional to the partial pressure of the gas above the liquid.
• The constant of proportionality is known as Henry's Law Constant (K_H).
• A higher Henry's Law constant indicates that the gas is less soluble in water.
• Mathematically, Henry's Law is represented as:

  C = K_H * P

  where,
  • C is the concentration of the gas in the liquid.
  • K_H is the Henry's Law constant.
  • P is the partial pressure of the gas.

EXPLANATION:

• The gases mentioned in the options (N₂, O₂, He, H₂) have different solubilities in water at 293 K.
• Among these gases, helium (He) has the highest Henry's Law constant.
• This means that helium is the least soluble gas in water at 293 K.
• The values of the Henry's Law constants are typically as follows:
  • N₂: 1.67 × 10^-5 mol/(L·atm)
  • O₂: 1.30 × 10^-5 mol/(L·atm)
  • He: 3.72 × 10^-4 mol/(L·atm)
  • H₂: 7.80 × 10^-5 mol/(L·atm)
• As seen, helium (He) has the highest Henry's Law constant, making it the correct answer.

Therefore, in water, helium (He) has the highest Henry's Law constant at 293 K.