1. what is analytical molarity? please explain with example.

2. what is equilibrium molarity? please give example.

3. why anlytical molarity of HCl is zero?

Analytical molarity: An analyst (Chemist) prepares 1,2,3 etc... Molar solutions by taking stipulated amounts of solute and solvent. These 1 M, 2M and 3M solutions may thermodynamically behave as 0.8M, 1.5M and 2.2M solutions. Then, these reduced concentrations as termed as active masses.

Active Mass= Activity coefficient x Analytical concentration; always activity coefficient is less than or equal to 1. Activity coefficient tends to 1, if concentration tends to zero. Activity coefficient of gases is called fugacity.

Equilibrium Molarity: It is the molarity, or concentration of a specified substance at the time independent thermodynamic state of dynamic equilibrium.

The total number of moles of a solute, regardless of state, in one liter of solution. Given as moles/L.

Calculate the equilibrium molarities of H2, I2, and HI
                              H2(g) + I2(g) <--> 2 HI(g)
Initial..................... 0.05.... 0.06 ...........0
Change...................- x ......- x..............+x
Equilibrium.......... 0.05 - x.. 0.06-x...........x

Equilibrium constant, Kc = [HI]2 / [H2] [I2] = 58.6
......................................… = [x]2 / [0.05-x] [0.06-x] = 58.6

Solve for x to get the change in the number of moles, and subsequently the number of moles of each compound in equilibrium

Molarity of H2 = [0.05-x] / 1.00L
Molarity of I2 = [0.06-x] / 1.00L
Molarity of HI = x / 1.00L (2)
Equivalent weight is the atomic weight of an element or radical divided by the valence it assumes in a chemical compound.