Question

Consider the following options and pick out the right choice. The solubility of a gas in sea water increases with ...............

• A. the increase of temperature, salinity and pressure
• B. the decrease of temperature, salinity and pressure
• C. the increase of temperature, and the decrease of salinity and pressure
• D. the decrease of temperature and salinity, and the increase of pressure

Hint:

Cold, less saline, and high-pressure deep waters hold maximum dissolved gases (like O$_2$ and CO$_2$).

Answer 1

The Correct Option is D

Step 1: Effect of temperature.
Gas solubility decreases with increasing temperature. Therefore, lower temperature → higher solubility.
Step 2: Effect of salinity.
Higher salinity reduces gas solubility (salting-out effect). Hence, lower salinity → higher solubility.
Step 3: Effect of pressure.
According to Henry’s law, solubility increases with pressure.
Step 4: Match with options.
The correct combination is: decrease in temperature, decrease in salinity, and increase in pressure → option (D). Final Answer: \[ \boxed{\text{(D) the decrease of temperature and salinity, and the increase of pressure}} \]