Asked in NUMS 2019 (cancelled sitting) 2019Moderate

What is the % relative humidity at 25 oC and 0.01876 atm if the vapor pressure of water is 23.76 mm Hg?

Correct answer: C. 60%

  • A. 40%
  • B. 50%
  • C. 60%
  • D. 70%

Explanation

Relative humidity is the ratio of the partial pressure of water vapor present in the air to the vapor pressure of water at a particular temperature, expressed as a percentage. In this question, we are given the vapor pressure of water (23.76 mm Hg) and the temperature (25 oC). We can use the formula: Relative Humidity = (Partial Pressure of Water Vapor / Vapor Pressure of Water) x 100 We need to first convert the given pressure of 0.01876 atm to mm Hg. 1 atm = 760 mm Hg, so 0.01876 atm = 14.268 mm Hg. Then, we can substitute the values in the formula: Relative Humidity = (14.268 / 23.76) x 100 = 60% Therefore, the % relative humidity at 25 oC and 0.01876 atm is 60%.

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