#Question id: 381
#Unit 1. Molecules and their Interaction Relevant to Biology
Consider an acetate buffer, initially at the same pH as its pKa (4.76). When sodium hydroxide (NaOH) is mixed with this buffer, the:
#Question id: 382
#Unit 1. Molecules and their Interaction Relevant to Biology
The molar ratio of sodium acetate to acetic acid in a buffer solution with a pH OF 5.76 is 10:1. Assuming the total buffer concentration is 2.2 X 10-2 mol/L, how many grams of sodium acetate (m.w. 82) and how many grams of acetic acid (m.w. 60) should be used in preparing a litre of the solution?
#Question id: 383
#Unit 1. Molecules and their Interaction Relevant to Biology
Three buffers are made by combining a 1 M solution of acetic acid with a 1 M solution of sodium acetate in the ratios shown below
|
1 M acetic acid |
1 M sodium acetate |
|
Buffer 1: 10 mL |
90 mL |
|
Buffer 2: 50 mL |
50 mL |
|
Buffer 3: 90 mL |
10 mL |
Which of these statements is true of the resulting buffers?
#Question id: 384
#Unit 1. Molecules and their Interaction Relevant to Biology
A solution was prepared by dissolving 0.02 moles of acetic acid (HOAc; pKa = 4.8) in water to give 1 liter of solution. What is the pH? To this solution was then added 0.008 moles of concentrated sodium hydroxide (NaOH). What is the new pH? (In this problem, you may ignore changes in volume due to the addition of NaOH).
#Question id: 386
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following properties of water does not contribute to the fitness of the aqueous environment for living organisms?
#Question id: 387
#Unit 1. Molecules and their Interaction Relevant to Biology
For a weak acid with a pKa of 6.0, What would be the ratio of acid to salt at pH 5.