Question

Calculate the pressure of the gas in the flask connected to the manometer.

1. Proom = 730 mmHg:

A) 84 and 127.
B) 26 and 130.
C) 95 and 95.

2. Proom = 733 mmHg:

A) 95 and 41.
B) 104 and 31.
C) 96 and 138.

Answer 1

To calculate the pressure of gas in a manometer, add or subtract the mercury level difference to the atmospheric pressure to get the pressure in mmHg, and then convert to atm or kPa using conversion factors.

Step-by-step explanation:

The pressure of a gas in a flask connected to a manometer can be calculated based on the difference in mercury levels between the two arms of the manometer and the known atmospheric pressure. If we assume that atmospheric pressure is 760 mmHg, and the difference in mercury level in the manometer is given, we add the difference to the atmospheric pressure if the mercury level is higher on the side open to the atmosphere, or subtract if it is lower. The total will give us the gas pressure in mmHg. This can then be converted to other units like atmospheres (atm) or kilopascals (kPa) using conversion factors.

For instance:

• If the mercury level is 137 mmHg higher on the side open to the atmosphere, the pressure of the gas would be 760 mmHg + 137 mmHg = 897 mmHg.
• To convert this to atm, we use the conversion factor of 1 atm = 760 mmHg, which results in 897 mmHg / 760 mmHg = 1.18 atm.
• To convert to kPa, we would use the conversion factor of 1 atm = 101.325 kPa, resulting in 1.18 atm x 101.325 kPa/atm = 119.56 kPa.