The maximum rate for withdrawing gaseous chlorine from a 1-ton tank at room temperature is:

The maximum rate for withdrawing gaseous chlorine from a 1-ton tank at room temperature is:

• A. 15 lb/h
• B. 5 lb/h
• C. 50 lb/h
• D. 100 lb/h

Answer: (A)

The main idea is that the withdrawal rate is limited by how fast liquid chlorine inside the pressurized cylinder can vaporize to replace what’s being drawn off. In a 1-ton cylinder, chlorine is stored as a liquid under high pressure; when you open the valve, gas flows out as liquid chlorine vaporizes to maintain the gas phase above it. The rate at which heat can transfer into the liquid from the surroundings determines how quickly it can vaporize. At room temperature, this heat input is limited, so the vaporization—and thus the flow—has a practical maximum. That limit is about 15 pounds per hour for a 1-ton cylinder. If you tried to withdraw more, the liquid would cool faster, lowering vapor pressure and reducing the outflow rate, so higher numbers aren’t supported under these conditions.

The main idea is that the withdrawal rate is limited by how fast liquid chlorine inside the pressurized cylinder can vaporize to replace what’s being drawn off. In a 1-ton cylinder, chlorine is stored as a liquid under high pressure; when you open the valve, gas flows out as liquid chlorine vaporizes to maintain the gas phase above it. The rate at which heat can transfer into the liquid from the surroundings determines how quickly it can vaporize. At room temperature, this heat input is limited, so the vaporization—and thus the flow—has a practical maximum. That limit is about 15 pounds per hour for a 1-ton cylinder. If you tried to withdraw more, the liquid would cool faster, lowering vapor pressure and reducing the outflow rate, so higher numbers aren’t supported under these conditions.