GENERAL CHEMISTRY 2

GENERAL CHEMISTRY 2

By Jesther Resuello (12STEM-03)

​INTERMOLECULAR FORCES - COLLIGITATIVE PROPERTIES

Multiple Choice

Known as Chemical Bonds

• Intramolecular

• Intermolecular

• Dispersion

• London

Multiple Choice

Attractive forces between molecules

• Intramolecular

• Intermolecular

• Dispersion

• London

INTERMOLECULAR FORCES

INTERMOLECULAR (IMF) vs INTRAMOLECULAR

• Are attractive forces between molecules.​

• Hold atoms together in a molecule

• Known as Chemical Bonds​

• Stronger then IMF

Multiple Choice

Which of the IMFs is found in all molecules?

• London

• Dipole-Dipole

• Hydrogen Bond

• Ion-DIpole

Multiple Choice

Mostly found in Ionic Bonds, strongest IMF

• London

• Dipole-Dipole

• Hydrogen Bond

• Ion-DIpole

Multiple Choice

Which of the IMFs is observable in Polar molecules but is weaker than H-Bond?

• London

• Dipole-Dipole

• Hydrogen Bond

• Ion-DIpole

Multiple Choice

Which of the IMFs is a special type of Dipole-Dipole and relatively stronger?

• London

• Dipole-Dipole

• Hydrogen Bond

• Ion-DIpole

TYPES OF INTERMOLECULAR FORCES

DISPERSION / LONDON FORCE

• Attractive forces that arise as a result of temporary dipoles (presence of difference in polarity) induced in atoms or molecules

• W​eakest

• Occurs in all molecules​

TYPES OF INTERMOLECULAR FORCES

DIPOLE-DIPOLE FORCE

• ​Attractive forces between polar molecules.

• ​Polar molecule has stronger IMF than nonpolar molecule since it contains both Dispersion & Dipole-Dipole forces.

TYPES OF INTERMOLECULAR FORCES

HYDROGEN BOND

• Strong dipole-dipole forces

• Special dipole-dipole interaction between they hydrogen atom in a polar N-H, O-H, or F-H bond and an electronegative O, N, or F atom.

• 2nd Strongest

TYPES OF INTERMOLECULAR FORCES

ION-DIPOLE FORCES

• Attractive forces between an ion and a polar molecule.

• S​trongest of them all.

TYPES OF INTERMOLECULAR FORCES

MUST REMEMBER

• Dispersion vs Dispersion = Battle of the mass

• The mo​re IMF, the stronger the force, the higher the boiling point and the lower the freezing point.

• Structure also affects IMF​

TYPES OF INTERMOLECULAR FORCES (EXERCISE)

EX​ERCISES

Determine what type of intermolecular forces exist in the following molecules: LiF, MgF₂, H₂O, and HF.

Multiple Choice

Which has the highest boiling point I_2, Br_2, and Cl₂

• Iodine Molecule

• Bromine Molecule

• Chlorine Molecule

• They have the same boiling point.

TYPES OF INTERMOLECULAR FORCES (EXERCISE)

EX​ERCISES

Which has the highest boiling point I_2, Br_2, and Cl₂

TYPES OF INTERMOLECULAR FORCES (EXERCISE)

EX​ERCISES

Rank the following in terms of increasing boiling point: LiCl C3H7OH C4H8 N2

PROPERTIES OF LIQUID

SURFACE TENSION

Amount of energy required to stretch or increase the surface of a liquid by a unit area.

VISCOSITY

Measure of a fluid’s resistance to flow. Influenced by shape and depends on the temperature.

PHYSICAL PROPERTIES OF SOLUTION

COHESION

is the intermolecular attraction between like/similar molecules

ADHESION

is an attraction between unlike molecules

Multiple Choice

Which Property of Liquid is measurement of a fluid resistance to flow?

• Surface Tension

• Viscosity

• Cohesion

• Adhesion

Multiple Choice

Which Property of Liquid is the amount of energy required to stretch

• Surface Tension

• Viscosity

• Cohesion

• Adhesion

Multiple Choice

Which Property of Liquid is the attraction between like molecules?

• Surface Tension

• Viscosity

• Cohesion

• Adhesion

Multiple Choice

Which Property of Liquid is the attraction between unlike molecules?

• Surface Tension

• Viscosity

• Cohesion

• Adhesion

Solute + Solve​

PROPERTIES OF LIQUID

SOLUTION

UNSATURATED​

solvent > solute​

SATURATED​

solvent = maxed out

SUPERSATURATED​

solute > solvent​

Multiple Choice

Universal Solvent

• Rugby

• H2O

• C6H12O6

• C6H8

Multiple Choice

Solvent has maxed-out

• Solution

• Supersaturated

• Saturated

• Unsaturated

Multiple Choice

Solute is greater than Solvent

• Solution

• Supersaturated

• Saturated

• Unsaturated

Multiple Choice

Solvent is greater than Solute

• Solution

• Supersaturated

• Saturated

• Unsaturated

SOLUTION PROCESS

ENDOTHERMIC vs EXOTHERMIC

• Breaking of Bonds​

• Forming of Bonds

Multiple Choice

Exothermic is the Breaking of bond

• Korek

• Mali

FACTORS AFFECTING SOLUBILITY

TEMPERATURE

• ​Solids

  • ​Solubility of a solid substance increases with temperature

• Gases

  • ​Solubility of gases in water usually decrease with increasing temperature

• Increase in Solubility = Increase in Pressure​

PRESSURE (G)

Multiple Choice

Increasing temperature = Increasing Solubility

• Solid

• Gas

• Liquid

• Aqueous

Multiple Choice

In water, solubility decreases with increasing temperature

• Solid

• Gas

• Liquid

• Aqueous

COLLIGATIVE PROPERTIES

ELECTROLYTE

• ​Results to 2 or more dissolve particle.

• Makes use of Van't Hoff Fact​or

Always result to 1 dissolve particle because they do not dissociate

NONELECTROLYTE

VAN'T HOFF FACTOR

NaCl​

Multiple Choice

NaCl

• Electrolyte

• Nonelectrolyte

Multiple Choice

Van't Hoff factor of NaCl

• 1

• 2

• 3

Multiple Choice

C6H8

• Electrolyte

• Nonelectrolyte

Multiple Choice

Van't Hoff factor of C6H8

• 1

• 2

• 14

Multiple Choice

Al(SO3)

• Electrolyte

• Nonelectrolyte

CONCENTRATION UNITS (FORMULAS)

COLLIGATIVE PROPERTIES

VAPOR PRESSURE

BOILING POINT

FREEZING POINT

OSMOTIC PRESSURE

CONCENTRATION UNITS (COMPUTATIONS)

EXERCISE

​Sea water contains roughly 20.3 kg of NaCl per 2 gallons. What is the molarity of sodium chloride in sea water (1 gal = 3785 mL)

Multiple Choice

​Sea water contains roughly 18.4 kg of NaCl per 1 gallons. What is the molarity of sodium chloride in sea water (1 gal = 3785 mL)

• 83.83

• 83.82

• 0.084

• 0.083

CONCENTRATION UNITS (COMPUTATIONS)

EXERCISE

​Calculate the molality of the following solution:

50.4% m/m KBr solution​

Multiple Choice

Calculate the molality of the following solution:

20.9% m/m Al2O3 solution​

• 2.59

• 2.61

• $$2.59\ x\ 10^{-3}$$  

• $$2.61\ x\ 10^{-3}$$  

CONCENTRATION UNITS (COMPUTATIONS)

EXERCISE

​A one liter stock solution of 70% dextrose solution is available but you are required to make 2 liter of 30% dextrose solution. How do you prepare this?

Multiple Choice

​A 100mL stock solution of 15.7% ascorbic acid solution is available but you are required to make 94 mL of 9.9% ascorbic acid solution. How do you prepare this? Final answer must be in mL.

• 0.059 mL

• 0.061 mL

• 59 mL

• 61 mL

COLLIGATIVE PROPERTIES (COMPUTATIONS)

EXERCISE

​A solution is prepared by dissolving 396g of sucrose (C12H22O11) in 624g of water. What is the vapor pressure of this solution at 30C (Vp of water at 30C is 31.8 mmHg)

Multiple Choice

​A solution is prepared by dissolving 523g of sucrose (C12H22O11) in 1.2 Kg of water. What is the vapor pressure of this solution at 30C (Vp of water at 30C is 31.8 mmHg).

• 0.978

• 31.1

• 31.01

• 31.11

COLLIGATIVE PROPERTIES (COMPUTATIONS)

EXERCISE

​What are the boiling point and freezing point of a 2.47 m solution of naphthalene in benzene? (The Bp and Fp of benzene are 80.1C and 5.5C respectively)

Multiple Select

​What are the boiling point and freezing point of a 5.89 m solution of naphthalene in benzene? (The Bp and Fp of benzene are 80.1C and 5.5C respectively)

Kb = 2.53

Kf = 5.12

Choose all the correct answer.

• Tb = 95C

• Tf = -24.66C

• Tb = 14.90C

• Tf = 30.16

• Tf = 24.66

COLLIGATIVE PROPERTIES (COMPUTATIONS)

EXERCISE

​What is the osmotic pressure (in atm) of a 1.36 M aqueous solution of Urea [(NH2)2CO] at 22C

Multiple Choice

​What is the osmotic pressure (in atm) of a 9.723 M aqueous solution of Urea [(NH2)2CO] at 54 C

• 261

• 261.1

• 262

• 260

​THANK YOU <3