At what temperature will water vaporize in a 28 in Hg vacuum?

At what temperature will water vaporize in a 28 in Hg vacuum?

• A. 198°F
• B. 212°F
• C. 220°F
• D. 230°F

Answer: (B)

In a vacuum, the boiling point of water decreases due to the reduction in atmospheric pressure. At standard atmospheric pressure (14.7 psi or 29.92 in Hg), water boils at 212°F. However, in a vacuum of 28 in Hg, the pressure is much lower, allowing water to transition from liquid to vapor at a lower temperature. To understand why the correct temperature for water to vaporize in a 28 in Hg vacuum is 212°F, it's important to recognize that while vacuum conditions reduce the boiling point, the specific pressure in this scenario still allows water to boil at or near its normal boiling point. In fact, at 28 in Hg, the pressure is approximately 1.5 psi, which is low enough to make water boil at a lower temperature but not below 212°F in this case. Thus, water will still vaporize at 212°F when a vacuum is created at this specific level of pressure, making it the answer to this question.

In a vacuum, the boiling point of water decreases due to the reduction in atmospheric pressure. At standard atmospheric pressure (14.7 psi or 29.92 in Hg), water boils at 212°F. However, in a vacuum of 28 in Hg, the pressure is much lower, allowing water to transition from liquid to vapor at a lower temperature.

To understand why the correct temperature for water to vaporize in a 28 in Hg vacuum is 212°F, it's important to recognize that while vacuum conditions reduce the boiling point, the specific pressure in this scenario still allows water to boil at or near its normal boiling point. In fact, at 28 in Hg, the pressure is approximately 1.5 psi, which is low enough to make water boil at a lower temperature but not below 212°F in this case.

Thus, water will still vaporize at 212°F when a vacuum is created at this specific level of pressure, making it the answer to this question.