Acids and Bases

Flashcards covering the key concepts of Acids and Bases

Strong Acids

Dissociate (ionize) totally (completely) in water to produce H3O+.

Strong Bases

Dissociate (ionize) totally (completely) in water to produce HO-.

Acids

Produce H+ when they dissociate in H2O and are proton (H+) donors.

Bases

Produce HO- when they dissociate in H2O and are proton (H+) acceptors.

pH Range for Acids

0 ≤ pH < 7

pH Range for Bases

7 < pH ≤ 14

pH Calculation for Strong Monoacid

pH = -log Ca; [H3O+] = Ca = 10-pH

pH Calculation for Strong Monobase at T=25oC

pH = 14 + logCb; [HO-] = Cb = 10pH-14

pH Calculation for Strong Diacid

pH = -log2Ca; [H3O+] = 2Ca = 10-pH

pH Calculation for Strong Dibase at T=25oC

pH = 14 + log2Cb; [HO-] = 2Cb = 10pH-14

Kw

[H3O+][HO-] = Kw

pH Change for Strong Acid Dilution

pH2 = pH1 + n; pH will increase by n-unit

pH Change for Strong Base Dilution

pH2 = pH1 - n; pH will decrease by n-unit

pH of Strong Acid

pH = -log [H3O+]

pH of Strong Base

pH = 14 + log [OH-]

Net Ionic Equation for Strong Acid and Strong Base

H3O+ (aq.) + OH- (aq.) → 2H2O

Acid-Base Titration Types

Volumetric titration/Colorimetric titration and PH-metric titration

Equivalence Point (Colorimetric)

Detected by change in color of the solution at equivalence.

Equivalence Point (PH-metric)

Determined graphically by using parallel tangent method.

Titration Equation

H3O+ (aq.) + HO- (aq.) 2 H2O (l)

Equivalence Point Equation

𝒏(𝐚𝐧𝐚𝐥𝐲𝐭𝐞)𝐩𝐥𝐚𝐜𝐞𝐝 𝐢𝐧 𝐛𝐞𝐚𝐤𝐞𝐫 𝟏 = 𝒏(𝐭𝐢𝐭𝐫𝐚𝐧𝐭)𝐚𝐝𝐝𝐞𝐝𝐟𝐫𝐨𝐦 𝐛𝐮𝐫𝐞𝐭 𝟏

Suitable indicator used in titration

Bromothymolblue because pHE = 7 is included in the pH-range of this indicator

Effect of adding distilled water on pHE at equivalence

No effect on pHE.

Effect of adding distilled water on VbE (volume of basic solution needed to reach equivalence)

Adding distilled water, doesn’t affect the number of moles of (H3O+) in the beaker, consequently VbE remains constant.