Calculate the number of moles of carbon dioxide produced with a gas volume of a 115 ml at a temperature of 21ﾟc and water vapor corrected pressure of 746 mm hg?

n = 0.005 mol

Explanation:

Given data:

Volume = 115 mL

Temperature = 21°C

Pressure = 746 mmHg

Number of moles = ?

Solution:

746 mmHg = 746 /760 = 0.98 atm

21°C = 21+273 = 294 K

115 mL /1000 = 0.115 L

PV = nRT

n = PV/RT

n = 0.98 atm ×  0.115 L / 0.0821 atm. L. mol⁻¹. K⁻¹ ×294 K

n = 0.1127 atm. L /24.14 atm. L. mol⁻¹

n = 0.005 mol

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.