Aballoon has a volume of 1.2 l at a pressure of 1.1 atm and a temperature of 25°c. if the temperature changes to 75ºc and the volume changes to 6.7 l, what is the new pressure?

P₂ = 0.23 atm

Explanation:

Given data:

Initial volume = 1.2 L

Initial pressure = 1.1 atm

Initial temperature = 25 °C (25 +273 = 298 K)

Final temperature = 75°C(75+273 = 348 K)

Final volume = 6.7 L

Final pressure = ?

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

P₂ = P₁V₁ T₂/ T₁ V₂  

P₂ = 1.1 atm × 1.2 L × 348 K / 298 K × 6.7 L  

P₂ = 459.36 atm .L. K / 1996.6 k.L

P₂ = 0.23 atm

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.