Question

1.Calculate the equilibrium constant at 25 °C for the weak base (CH₃)₂NH. Its weak acid is (CH₃)₂NH₂⁺ , K_a = 1.7 x 10^-11

Please use decimal notation and use two digits (e.g. 0.0025).

2.Select the correct reaction when NH₂^- (a Bronsted-Lowry base) reacts with water.

a.NH₂^-   +   H₂O  ⇄ NH^_2- + H₃O⁺

^b. NH₂^-   +   H₂O  ⇄ NH₃ + OH^-

^c.NH₂^-   +   H₃O⁺  ⇄ NH₃ + H₂O

d.NH₂^-   + OH^-  ⇄ NH^_2- + H₃O⁺

^3. For a precipitate (solid) to form in aqueous solution, which condition needs to be met?

Assume the reaction is

AgCl(s)  ⇄ Ag⁺_(aq) + Cl^-_(aq)

	1.	K = 0
	2.	K << 1
	3.	K >> 1
	4.	None of these answers

Answer 1