Acids and Bases. Drill – 5/6/11. What happens when you mix an acid and a base?. Drill – 5/9/11. Write the equation for the neutralization reaction between carbonic acid (H 2 CO 3 ) and calcium hydroxide. Drill – 5/11/11.
Acids and Bases
Identify the following as acid, base, conjugate acid, and conjugate base:
HBr + H20 H30+ + Br-
ACIDS & BASES
Acid = substance that releases H+ ions in aq solution
HCl H+ + Cl-
Base = substance that releases OH-ions in aq solution
NaOH Na+ + OH-
HCl + NaOH NaCl + H2O
As more and more substances were determined to have acidic or basic properties, even some without obvious H+ or OH-, a new definition was needed.
H2O + HCl H3O+ + Cl-
NH3 + H2O NH4+ + OH–
A + :B → A—B
Start with hydro-
End with –ic acid
“I ate something, and now I am sick”
If anion ends in –ate then the acid ends in –ic
If the anion ends in –ite then the acid ends in -ous
A stronger acid will transfer MORE protons (H+) than a weak acid. It will create more hydronium ions (H3O+) in water.
HCl + H2O H3O+ + Cl-
CH3COOH + H2O H3O+ + CH3COO-
How do we compare the strength of an acid or a base?
We measure the amount of hydronium ions they create (acids) or the amount of hydroxide ions they create (bases)….using concentration.
Water is simultaneously donating and accepting protons!
With an increase in [H30+], some of the H30+ ions will react with the OH- ions, reducing [OH-] . [H30+][OH-] will still = 1.0x10-14
Whenever [OH-] is greater than [H30+], the solution is basic.
pH = -log [H30+]
pOH = -log [OH-]
[H+] = 1 x 10-3 = 0.001
pH = -log [H+]
pH = -log (1 x 10-3)
pH = 3
To determine pH from a concentration where 1 is the only digit, write the concentration in scientific notation. The absolute power of the exponent will be the pH.