28. What is meant by the statement "Pressure of gas is 13.6 cm of Hg"?
a. Density of mercury is 13.6 g cm
b. At sea level mercury barometer reads 13.6 cm.
C. Pressure is equivalent to that of 13.6 cm mercury column.
d. Pressure is equal to 13.6 atmospheres.
Answers
Answer:
A. Density of mercury is 13.6 g cm.
Answer:
The statement " Pressure of gas is 13.6cm of Hg" means that the pressure of that gas is equal to that of 13.6 cm mercury column
The answer is C
Explanation:
When measuring pressure using a mercury barometer, the pressure is given by the height of the column of mercury in the glass tube.
In a mercury barometer, the pressure that is exerted on the reservoir mercury, causes the mercury in the glass tube to rise until a balance is struck.
The height at which the mercury in the glass column has risen is used as an equivalent measure of the pressure of the gas/air.
The air pressure at sea level is about 760 mmHg or 76cmHg. This is the height at which the air pressure causes the mercury to rise in the glass tube of the barometer which is 760mm or 76cm.
In this case, the gas in question has a pressure of 13.6cmHg. This means that if the gas was to exert pressure on the reservoir mercury on the barometer, the height at which the mercury will rise in the glass tube of the barometer will be 13.6cm.
Therefore the pressure of this gas is 13.6 cm of mercury, which corresponds to the height the pressure exerted by the gas can cause the mercury to rise in the glass tube.