A1.50-liter sample of dry air in a cylinder exerts a pressure of 3.0 atmospheres at a temperature of 25°c. without change in temperature, a piston is moved in the cylinder until the pressure in the cylinder is reduced to 1.0 atmosphere. what is the volume of the gas? (be sure to use the correct number of significant figures.) 0.22 l 0.50 l 2.0 l 4.5 l

4.5 L.

Explanation:

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R  is the general gas constant,

T is the temperature of the gas in K.

(P₁V₁) = (P₂V₂)

P₁ = 3.0 atm, V₁ = 1.5 L,

P₂ = 1.0 atm, V₂ = ??? L.

(P₁V₁) = (P₂V₂)

∴ V₂ = (P₁V₁)/P₂ = (1.5 L)(3.0 atm)/(1.0 atm) = 4.5 L.

So, the right choice is: 4.5 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.