pH and Buffer Flashcards
What does it mean by equivalence point ?
Its the number of moles of H + and OH- in a mixture which is equal .
What’s the description of pH ?
its the measure of the amount of hydronium in H+ in a solution .
What is Buffer ?
Its a substance which tries minimise changes in concentration of H+ and OH- in a solution .It does by accepting hydrogen ions from the solution when its decreased .
What do Buffers help with ?
Buffers helps allows biological fluids to maintain a constants pH despite the addition of acids/bases.
Consists of weak acids or its conjugate base /weak base and conjugate acid .
What are the three categories ?
Neutral : There’s equal amounts of OH-/H - substances
Acids : Greater amounts of H + substances
Base : greater amounts of OH-
What does PKA determine ?
Determined the acids strength
The lower the pKa the stronger the acid .
Stronger acids deprotonate completely this is because of transfer of every acidic proton to solvent etc. .
Weak acids : Partially due to generating some conjugate acids and partially due to weak
What happens during this reaction and identify the conjugate acid and base vice versa?
H2CO3 (l) + H2O(l) ⇌ HCO−3 (aq) + H3O+(aq).
Acid Base Acid + Base
H2C03 = Is the acid because it donates a proton .
H20 = is the base because it took away a proton from H2C03 .
HCO-3 = Conjugate acid
H30+=Base
What happens during this reaction ?
HCI +NH3- NH4+CI -
HCI :is the acid
NH3- Is the Base
NH4 - Base
C1- ACID
What is acid ?
Acid is defined as a substance which gives up a hydrogen proton
What is a base ?
Accepts a proton .
bases are substances that, in aqueous solution, release hydroxide (OH−) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons …
Is a H+ ion a proton ?
Yes because if hydrogen ion looses its electron all that’s left is proton which comprises nucleus
What does H+ ions immediately do in water and form ?
They immediately react with water to form H30+
What do we mean by the Bronsted Lowery acid and bases ?
Acid donate protons and Bases accept the protons .
What do mean by acid strength ?
acid to donate H+ ions in water
A strong acid completely dissociates into ions in water
Leads to a high concentration of H+, equal to the concentration of acid that was added. E.g.,
