The combustion of propane occurs when propane interacts with oxygen gas to produce water and carbon dioxide in the following reaction:
c3h8 (g) + 5o2(g) => 3co2 (g) + 4h2o (l)
if 2 moles of propane c3h8 (g) react at 373 k in a volume of 2.5 l, what is the resulting pressure in the cylinder from the co (g) produced in the reaction?

             Pressure =  73.49 atm

Explanation:

The balance chemical equation is as follow,

                                   C₃H₈ + 5 O₂  →  3 CO₂ + 4 H₂O

According to balanced equation,

           1 mole of C₃H₈ on combustion gives  =  3 moles of CO₂

So,

    2 moles of C₃H₈ on combustion will give  =  X moles of CO₂

Solving for X,

                      X  =  2 moles of C₃H₈ × 3 moles of CO₂ ÷ 1 mole of C₃H₈

                      X =  6 moles of CO₂

Now, in second step we will calculate the the pressure exerted by CO₂ at 2.5 L volume and 373 K temperature. For this we will use Ideal gas equation assuming the gas is acting as an ideal gas. Therefore,

Data:

       Temperature  =  T = 373 K

       Volume  =  V  =  2.5 L

       Moles  =  n  =  6 mol   ∴ As calculated above.

       Gas Constant  =  R  =  0.0821 atm.L.mol⁻¹.K⁻¹

Formula Used:

                         P V = n R T

Solving for P,

                          P = n R T / V

Putting Values,

                          P = 6 mol × 0.0821 atm.L.mol⁻¹.K⁻¹ × 373 K ÷ 2.5 L

                         P =  73.49 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.