I need help with chemistry. How do I write an algebraic Keq for...?

Question

1) 0.5 M Na OH NaOH (shifts back and forth) Na+ + OH-
2) 0.7 M N2O4 N2O4 (shifts back and forth) NO2
3) 0.3 M H3PO4 H2O + H3PO4 (shifts back and forth) H3O+ + PO4 3-
I am lost and confused on what to do. Please help me. Thank You.

Answer 1

i am lost and confused as to what the question/problem is. please elucidate.

Answer 2

In general for any reaction where C dissociates into x*A and y*B

C <------> x*A + y*B

the equilibrium constant is defined as

Keq = [A]^x * [B]^y / [C]

where [A], [B], and [C] are the concentrations of those components.

However, [C] is the concentration of the compound after dissociation,



1)

Keq = [Na]*[OH] / {[NaOH] - [Na]}

[NaOH] = 0.5 M

2)

Keq = [NO2]^2 / {[N2O4] - [NO2]}

[N2O4] = 0.7 M

3

Keq = [H3O]*[PO4] / {[H3PO4 - [PO4]}

[H3PO4] = 0.3 M