Chapter 21 Key Concepts

Question 1

Two methids for making a buffer solution

Answer 1

mix a weak acid with its salt
eg add 1.CA to water and you set up an equilib. only a small amount of the CA acc dissociates
2.add the caboxylate salt to water and it dissociates into its ions. then you have a source of carboxylate ions

partial neutralization of the weak acid
add alkali/base/metal/ammonia.WA partially neut making the CB. end up with mixture oif unreacted acid and CB

Question 2

when is the buffer most effective?

Answer 2

when con of acid and cb ae equal . so pH or buffer equals pKa of acid

Question 3

what does the Ph of an buffer depend on?

Answer 3

ratio of con of weak acid and conjuage base

pKa of acid

Question 4

what happens when pH less than 7.35

Answer 4

acidosis
-fatigue
shortness of breath
inextreme cases, shock or death.

Question 5

what happens when pH more than 7.45

Answer 5

alkalosis
-muscle spasms
light headeadness
nausea

Question 6

body makes more acidic things than alkaline things which it converts to H2CO3 by H+ plus the hydrogen carbonate. how is carbonic acid build up prevented?

Answer 6

convert it to C02 which is then exhaled by the lungs

Question 7

Use of indicator

Answer 7

monitor neutralization reaction accurately

Question 8

Choosing the inicator

Answer 8

indicartor must hve a colour change that coincides with the vertical point of the the pH curve.