Ch 13: Acids & Bases

Acids

100

What does a Lewis acid do?

Accepts an electron pair 

*Remember: 

Arrhenius - H⁺ produces H₃O⁺

Bronsted-Lowry - H⁺ donor 

200

Name the six strong acids. 

1. HCl

2.H2SO4

3. HI 

4. HBr

5.HClO4 

6. HNO3

6. 

300

What is the conjugate acid in the following chemical reaction? 

NH₂^- (aq) + H₂O (l) <--> NH₃ (aq) + OH^- (aq)

NH₃ 

*Conjugate acid is formed when the proton is transferred to the base. 

(Water is the acid & NH₂^- is the base) 

400

Which of the following is an oxyacid? 

a. HCl

b. H2S

c. HClO 

c. HClO

* Oxyacid: acidic proton attached to an oxygen atom 

500

Which of the following acids is the strongest? 

a. C₆H₅CO_{2  (}pKa = 4.20)

b. CH₃COOH  (Ka = 1.8 x 10^-5)

c. CH₂CICOOH (pKa = 2.87) 

c. CH2CICOOH

*Remember: 

The smaller the pKa value, the stronger the acid 

pKa = -log(Ka) 

b. pKa = 4.74

Bases

100

What does a Bronsted-Lowry base do? 

Accepts an H⁺ (proton) 

*Remember: 

Arrhenius - bases produce OH^- (hydroxide) 

Lewis - electron-pair donor 

200

Which of the following is a weak base? 

a. RbOH

b. CH3CH2

c. Ba(OH)2

b. CH3CH2 

Strong Bases: 

- Group 1/ heavy group 2 + (-OH)

*most weak bases are molecular (covalent) 

300

What is the conjugate base in the following reaction? 

HCl (aq) + H2O (l) --> H3O+ (aq) + Cl - (aq) 

Cl - 

Conjugate base: everything that remains of the acid molecule after a proton is lost 

400

Strong bases have ______% degree of ionization when dissolved in an aqueous solution. 

100% 

pH

100

What is the pH of blood? 

7.42

*Remember: 

Decreasing blood pH = Acidosis

Increasing blood pH = Alkalosis 

200

Write the formula to find pH from [H+].

pH = - log [H+]

300

pH decreases as what in a chemical reaction increases? 

The concentration of an acid 

*Remember: 

Acids pH is lower than 7

400

Calculate the pH and pOH os 0.0235 M HCl at 25 C. 

pH = 1.629

pOH = 12.371

500

A solution has a pOH that is 6.85. 

Calculate the pH, [H+], and [OH-]. 

14 = pH + pOH 

[H+] = antilog[pH]

[OH-]= antilog[pOH] 

Antilog = 10^-pH

pH = 7.15

[H+] = 7.08x 10^-8 M

[OH-] = 1.41 x 10^-7 M

Salts

100

What are the components of a salt? 

Cation (+) & Anion (-)

200

Strong Acid + Strong Base --> 

(What type of salt does it yield?)

Neutral Salt + H₂O

300

Weak Acid + Strong Base --> 

(What type of salt does it yield?)

Basic Salt + H₂O

400

Strong Acid + Weak Base -->

(What type of salt does it yield?) 

Acidic Salt + H₂O

500

Which of the following salts will produce a basic solution when it is dissolved in water? 

a. NaCl 

b. LiCl 

c. KF

c. KF 

* Weak acid + strong base --> basic 

KF + H2O --> HF (weak acid) + KOH (strong base) 

Equilibrium

100

Which way does equilibrium lie for a weak acid? 

It lies far to the left 

(Weak acids yields a strong conjugate base) 

200

What is the generic formula for acid dissociation? 

Ka = [A-][H+] / [HA]

300

@25 C, Kw = [H₃O⁺][OH^- ]. Kw = 1.0 x 10 ^-14. 

What is the [H₃O⁺] if the [OH] = 2.5 x 10^-3M? 

4.00 x 10^-12 M