Question #2fb3b

1 Answer
Jan 17, 2017

The answer will depend on the nature of the manometer. See the choices below...


The question does not indicate which of the two cases in the diagram below is the situation. I will answer for both:

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If we are looking at the centre situation, the pressure in the bulb is less than the pressure of the atmosphere, by an amount equal to h. In other words, it is #750-165 = 585 mmHg# which is converted to atmospheres by dividing by 760 mmHg (the equivalent of one atmosphere in mmHg). So, it is 0.77 atm.

To change this to kPa, multiply bu 101.32 (one atmosphere in kPa). The result is 78.0 kPa.

If the situation is the one on the right, the analysis is largely the same, but you add 165 mmHg to the pressure of the barometer as the pressure in the bulb is greater.

In this case, we get #P_(gas)=915mmHg, 1.20 atm or 122 kPa#