Apump contains 0.5 l of air at 203kpa. you draw back on the piston of the pump until the pressure reads 25.4kpa. what is the volume of air in the pump?

a. 0.2l
b. 1.0l
c. 4.0l
d. 2.0l

= 4.0 L

Boyle's law states that the volume of a fixed mass of a gas is inversely proportional to pressure at a constant temperature.

Therefore; Volume α 1/pressure

Mathematically; V α 1/P

V = kP, where k is a constant;

P1V1 = P2V2

V1 = 0.5 l, P1 =203 kPa, P2 = 25.4 kPa

V2 = (0.5 × 203 )/25.4

    = 3.996

   ≈ 4.0 L

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.

the answer is a! (2.9 x 10^-18 j) hope i could someone. : )