# Problem: Trimethylamine, (CH3)3N, is a weak base (Kb = 6.4 × 10–5) that hydrolyzes by the followingequilibrium: (CH3)3N + H2O → (CH3)3NH+ + OH– What is the pH of a 0.1 M solution of (CH 3)3NH+? (Enter pH to 2 decimal places; hundredth's.)

89% (50 ratings)
###### FREE Expert Solution

For this problem, we know that Trimethylamine, (CH3)3N, is a weak base (Kb = 6.4 × 10–5) and hydrolyzes by the following equilibrium:

(CH3)3N + H2O → (CH3)3NH+ + OH

We need to do these steps to solve for the pH of a 0.1 M solution of (CH3)3NH+

1. Write the equilibrium expression for (CH3)3NH+ in H2O

2. Make an ICE chart to solve for [H3O+] (in M or moles/L) at equilibrium

• Find Ka given Kb
• Recall that:

3. Solve for pH

Recall that pH is given by the equation:

89% (50 ratings) ###### Problem Details

Trimethylamine, (CH3)3N, is a weak base (Kb = 6.4 × 10–5) that hydrolyzes by the following

equilibrium: (CH3)3N + H2O → (CH3)3NH+ + OH

What is the pH of a 0.1 M solution of (CH 3)3NH+? (Enter pH to 2 decimal places; hundredth's.)