CHM271 Tutorial Ionic Equilibrium Answer( Student) PDF

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TUTORIAL 3 CHM271 PRINCIPLES OF PHYSICAL CHEMISTRYPrepared by : NORTHAQIFAH HASNA BINTI MOHAMED KHIR NURUL AMNI BINTI ABDULLAHCHAPTER 3 : IONIC EQUILIBRIUM_ANSWERA. Theories of Acid & Base, Conjugate Paira. Acid Base Arrhenius Arrhenius acids are subtances that ionises in aqueous solution to pro...

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TUTORIAL 3 CHM271 PRINCIPLES OF PHYSICAL CHEMISTRY

CHAPTER 3 : IONIC EQUILIBRIUM_ANSWER A. Theories of Acid & Base, Conjugate Pair a. Arrhenius

Acid Base Arrhenius acids are subtances that ionises in Arrhenius bases are subtances that ionises in aqueous solution to produce hydrogen, H+ or aqueous solution to produce hydroxide, OHhydronium, H3O+ ions. ions. HCl (aq) + H2O (l) ⇌ H3O+ (aq) + Cl- (aq)

BronstedLowry

Bronsted-Lowry acids act as proton donor, Bronsted-Lowry bases act as proton substances that donate a proton, H+ ion to acceptor, substances that accept a proton, H+ another substance. ion from another substance. HCl (aq) + H2O (l) ⇌ H3O+ (aq) + Cl- (aq)

Lewis

NaOH (aq) ⇌ Na+ (aq) + OH- (aq)

NH3 (aq) + HCl (l) ⇌ NH4+ (aq) + Cl- (aq)

Lewis acids are substances that accept a pair Lewis bases are substances that donate a of electrons, e- to form coordinate or dative pair of electrons, e- to form coordinate or bond; also known as electron acceptors. dative bond; also known as electron donors. Cu2+ (aq) + 6H2O (aq) ⇌ [ Cu(H2O)6 ]2+ (aq)

NH3 + BF3 ⇌ BF3•NH3

b. a) b) c)

c.

Bronsted acid HSO4‾ NH4+ H2O [Fe(H20)6]3+

Conjugate Acid H3O+ H3O+ N2H5+ H3O+

a) CaO b) CH3COCl c) CO

Prepared by : NORTHAQIFAH HASNA BINTI MOHAMED KHIR NURUL AMNI BINTI ABDULLAH

TUTORIAL 3 CHM271 PRINCIPLES OF PHYSICAL CHEMISTRY

B. Calculation of pH, pOH, Kw, Ka, Kb, pKa, pKb 1.

a. 2.0 b. 0.70 c. 0.40 d. 13 e. 13

2.

a) b) c) d)

2.82 × 10-3 M 0.011 M 1.79 x 10-12 M 3.16 x 10-4 M

3.

a) b) c)

5.01 x 10-10 M 2.22 x 10-10 M 6.31 x 10-5 M

4.

Fill in the blanks. Acid Methanoic acid, HCOOH Ethanoic acid, CH3COOH Hydrocyanic acid, HCN Nitrous acid, HNO2 Carbonic acid, H2CO3 Hydrofluoric acid, HF

Ka 1.70 × 10-4 1.80 × 10-5 4.90 × 10-10 4.50 × 10-4 4.47 × 10-7 7.10 × 10-4

pKa

Base Ammonia, NH3 Hydrazine, N2H4 Ethylamine, C2H5NH2 Phenylamine, C6H5NH2 Urea, (NH2)2CO

Kb 1.80 × 10-5 1.80 × 10-5 5.60 × 10-4 3.80 × 10-10 1.5 × 10-14

pKb

5.

a) 6.67 x 10 -4 b) 6.7 %

6.

1.00 x 10-5 M

7.

2.00 x 10-3 M

8.

a) 3.24 x 10-8 b) 7.49

3.77 4.74 9.31 3.35 6.35 3.15

4.74 4.74 5.25 9.42 13.82

Prepared by : NORTHAQIFAH HASNA BINTI MOHAMED KHIR NURUL AMNI BINTI ABDULLAH

TUTORIAL 3 CHM271 PRINCIPLES OF PHYSICAL CHEMISTRY

C. SALT HYDROLYSIS 1.

a) CH3NH3+ + H2O ⇌ CH3NH2 + H3O+ (acidic) b) F - + H2O ⇌ HF + OH- (basic) c) CO3 2- + H2O ⇌ HCO3- + OH- (basic) d) Neutral e) NH4+ + H2O ⇌ NH3 + H3O+ (acidic) f) Neutral g) C6H5COO- + H2O ⇌ C6H5COOH + OH- (basic)

2. 3.

Basic, 11.45 Acidic, 5.02

4.

Basic, 11.81

5

9.36

6

10.32

7

8.54

8

5.27

9

5.78

10

5.13

BUFFER SOLUTIONS 1

3.97

2

7.19

3

4.30

4

6.58

Prepared by : NORTHAQIFAH HASNA BINTI MOHAMED KHIR NURUL AMNI BINTI ABDULLAH...