A 2.320 mol quantity of NOCl was initially placed in a 1.750 L reaction chamber at 400°C. After equilibrium was established, it was found that 28.70 percent of the NOCl has dissociated: 2NOCl(g) ⇆ 2NO(g) + Cl2(g) Calculate the equilibrium constant Kc for the reaction.

Kc = 0.0307

Explanation:

Step 1: Data given

Number of moles NOCl = 2.320 moles

Volume = 1.750 L

Temperature = 400 °C

NOCl was 28.70 % dissociated

Step 2: The balanced equation

2NOCl(g) ⇔ 2NO(g) + Cl2(g)

Step 3: Calculate molarity NOCl

[NOCl] = moles / volume

[NOCl] = 2.320 moles / 1.750 L

[NOCl] = 1.326 M

Step 4: Initial concentration

[NOCl] = 1.326 M

[NO] = 0M

[Cl2] = 0M

Step 5: Concentration at equilibrium

For 2 moles NOCl we'll have 2 moles NO and 1 mol Cl2

[NOCl] = (1.326 -2X)M

[NO] = 2X M

[Cl2] = XM

Since NOCl is 28.70 % dissociated

([NOCl]0 -[NOCl]equi) = 0.2870[NOCl]0

2x = 0.2870(1.326) ⇒ x  =0.190

Step 6: Calculate Kc

Kc = [NO]²[Cl2] / [NOCl]²

Kc = (2x)²*x /(1.326 - 2x)²

Kc = [2(0.190)]² * (0.190)  / [1.326 - 2(0.190)]²

Kc = 0.0307

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.