Calculate the degree of dissociation and oh conc in 0.1m (nh4)3po4 having alpha 50%
To calculate the degree of dissociation (α) and the hydroxide ion concentration ([OH-]) in a 0.1 M (NH4)3PO4 solution with an alpha (α) value of 50%, you need to understand the dissociation reaction and equilibrium involved.
(NH4)3PO4 (aq) ⇌ 3 NH4+ (aq) + PO4^3- (aq)
The degree of dissociation (α) represents the fraction of the compound that dissociates into its constituent ions. In this case, α = 50% or 0.5.
Since (NH4)3PO4 dissociates into NH4+ and PO4^3-, and the initial concentration of (NH4)3PO4 is 0.1 M, we can calculate the concentration of NH4+ and PO4^3- ions using the degree of dissociation.
NH4+ concentration = 3 × 0.1 M × α (since there are three NH4+ ions formed per (NH4)3PO4 molecule)
PO4^3- concentration = 0.1 M × α (since there is one PO4^3- ion formed per (NH4)3PO4 molecule)
Using α = 0.5,
NH4+ concentration = 3 × 0.1 M × 0.5 = 0.15 M
PO4^3- concentration = 0.1 M × 0.5 = 0.05 M
Now, we need to consider the dissociation of water:
H2O (l) ⇌ H+ (aq) + OH- (aq)
In this reaction, water molecules can ionize to form equal concentrations of H+ and OH- ions. Since the concentration of H+ ions is equal to that of NH4+ ions (0.15 M), the OH- concentration will be equal to the PO4^3- concentration. Therefore,
OH- concentration = 0.05 M
Hence, the degree of dissociation (α) is 50% and the hydroxide ion concentration ([OH-]) in the 0.1 M (NH4)3PO4 solution is 0.05 M.