What is the pressure of the gas in a manometer if the height in between is 71mm and the atmospheric pressure is 761mmHg?
Is this something like your set up? This site will calculate it for you or show you how.
http://www.efunda.com/formulae/fluids/manometer.cfm
To determine the pressure of the gas in a manometer, you need to understand how a manometer works. A manometer is a device used to measure the difference in pressure between two regions, typically a gas and atmospheric pressure.
In this case, the height of the fluid in the manometer is given as 71 mm, and the atmospheric pressure is 761 mmHg. The pressure in the manometer can be calculated by subtracting the height of the fluid from the atmospheric pressure.
Pressure difference = Atmospheric pressure - Fluid height
Substituting the values:
Pressure difference = 761 mmHg - 71 mmHg
Now, subtract the fluid height from the atmospheric pressure:
Pressure difference = 690 mmHg
Therefore, the pressure of the gas in the manometer is 690 mmHg.