TLS Online TPP Program

#Question id: 10979


Which of the following conditions at the A-V node will cause a decrease in heart rate?

#7. System Physiology – Animal
  1. Increased sodium permeability
  2. Increased norepinephrine levels
  3. Increased potassium permeability
  4. Increased calcium permeability
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TLS Online TPP Program

#Question id: 378

#1. Molecules and their Interaction Relevant to Biology

Which of the following statements about buffers is true?

TLS Online TPP Program

#Question id: 379

#1. Molecules and their Interaction Relevant to Biology

A compound has a pKa of 7.4. To 100 mL of a 1.0 M solution of this compound at pH 8.0 is added 30 mL of 1.0 M hydrochloric acid. The resulting solution is pH:

TLS Online TPP Program

#Question id: 380

#1. Molecules and their Interaction Relevant to Biology

The Henderson-Hasselbalch equation:

TLS Online TPP Program

#Question id: 381

#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:

TLS Online TPP Program

#Question id: 382

#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?

TLS Online TPP Program

#Question id: 383

#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?