Chm lab 7 - Grade: B+ PDF

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Jonathan Ndjankoum October 19th, 2020 CHM-1045L

LAB 7: LEWIS STRUCTURES AND EFFECT OF POLARITY ON MISCIBILITY AND SOLUBILITY

This experiment will help us furthering our knowledge on how chemical and physical properties of a compound can be determined and highlighted through these steps: Lewis structure, Electronic and Molecular geometry, Polarity and, Intermolecular forces. This experiment aimed to associate Lewis structures with electron domain geometries and view the effect of lone pairs of electrons on molecular shapes. Next we study miscibility and immiscibility when the mixing together certain solution and, finally we‘ll study the solubility of solutes to certain solvent and the influence of polarity on liquids'. Next, it was found that sodium chloride was soluble in water, but insoluble in ethanol and cyclohexane. It was found that sucrose was soluble in water, but insoluble in ethanol and cyclohexane. Naphthalene was found to be insoluble in water and ethanol, but soluble in cyclohexane.

Part 1: Lewis Structure

Pre-lab:

Formal Charges Formula = V-N-B/2 V= number of valence electrons N= number of nonbonding valence electrons B= total number of electrons shared in bonds

Compound Formal Electronic Molecular Hybridization Polarity s Charges Geometry Geometry

IF5

(F.C) I= 0 and (F.C) F= 0

Octahedral

Square Pyramidal

sp³d²

Polar

SeF4

(F.C) Se= +1 and (F.C) F= +3

Trigonal Bipyramidal

Seesaw

sp³d

Polar

Lewis Structure

NF3

(F.C) N= +1 and (F.C) F= +3

C2H4

(F.C) C= 0 and (F.C) H= 0

BeI2

(F.C) Be= 0 and (F.C) I= +3

Linear

ClO4-

(F.C) O= -1, (F.C) Cl= 0 and, (F.C) O= 0

Tetrahedral

Tetrahedral

Trigonal Pyramidal

sp ³

Polar

sp²

Non-Polar

Linear

sp

Non-Polar

Tetrahedral

sp ³

Non-Polar

Trigonal Planar Trigonal Planar

XeF4

(F.C) Xe= +3 and (F.C) F= 3

Octahedral

Square Planar

sp³d

Non-Polar

TeH6

(F.C) Te= 0 and (F.C) H= 0

Octahedral

Octahedral

sp³d²

Non-Polar

T-Shaped

sp³d

Non-Polar

Square Planar

sp³

Non-Polar

XeF3+

ICl4-

(F.C) F_1= +1, (F.C) Trigonal Planar Xe= 0 and (F.C) F_2= 0

(F.C) I= -1 and (F.C) Cl= 0

Octahedral

NO2+

(F.C) O= -1, (F.C) N= 0 and, (F.C) O= 0

Bent

Trigonal Planar

sp

Non-Polar

NO2-

(F.C) O= +1, (F.C) N= 0 and, (F.C) O= 0

Bent

Trigonal Planar

sp

Polar

Observation: During this part of the experiment we worked on establishing the formal charges, electronic geometry, molecular geometry, hybridization, polarity on Lewis Structure of several chemical compounds. IF5 was found to have an octahedral electron domain geometry and a square pyramidal molecular geometry. SeF4 was found to have a Trigonal Bipyramidal electron domain of geometry and, has a seesaw molecular geometry, next NF3 had a Tetrahedral electron geometry and Trigonal Pyramidal molecular geometry.C2H4 was found to have a Trigonal Planar electron domain geometry and a Trigonal Planar for molecular geometry, BeI2 was found to have a Linear electron domain of geometry and Linear molecular geometry. CLO4- was found to have a Tetrahedral electron domain of geometry and a Tetrahedral molecular geometry. XeF4 was found to have an Octahedral electron domain of geometry and a Square Planar molecular geometry.

TeH6 XeF4 was found to have an Octahedral electron domain of geometry and an Octahedral molecular geometry. XeF3+ was found to have a Trigonal Planar electron domain of geometry and a T-shaped molecular geometry. ICl4- was found to have an Octahedral electron domain of geometry and a Square Planar molecular geometry. NO2+ was found to have a bent electron domain of geometry and a trigonal planar molecular geometry. NO2- was found to have a bent electron domain of geometry and a trigonal planar molecular geometry.

Part B: Miscibility Mixtures Hexane/Water Ethanol/Hexane Ethanol/Water

Observations Both don’t mix with each other Hexane floats on top of the water The liquid solution looks homogenous The liquid solution looks homogenous

Observation: When we observed the Hexane/Water mixture we could clearly see one that one compound was floating above the other. When observing the Ethanol/Hexane mixture, the solution mix perfectly. Finally, when we observed the Ethanol/Water mixture , the solution mix First, we found that water was miscible in ethanol as the liquid solution looks homogenous but was immiscible

in hexane as one float on tops of the other, and hexane was miscible in ethanol as the liquid solution looks homogenous. perfectly.

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Part C: Solubility

Observations solvent Solutes Water

Ethanol

Hexane

NaCl

Fully dissolves

Not dissolves

Not dissolves

Sucrose

Fully dissolves

Not dissolves

Partial dissolves

Naphthalene

Not dissolves

Not dissolves

Fully dissolves

Observation: When we introduce NaCl in water it fully dissolves, when introduced in Ethanol and Hexane, it doesn’t dissolve. When we introduced sucrose in water in fully dissolves, when introduced in Ethanol it doesn’t dissolves and in Hexane it partially dissolves. When we introduce Naphthalene in water and Ethanol it doesn’t dissolves but fully dissolves in Hexane.

This part of the experiment helps us identifying the solubility of solids when exposed to a series of different solvents (Water, Ethanol and, Hexane). From our findings we established that water can fully hydrolyze NaCl and Sucrose but has no effect on

Naphthalene; next we studied sucrose solubility. It fully hydrolyzes in water but when exposed to organic compounds such as Ethanol and Hexane it becomes less soluble. Finally when we studied Naphthalene it didn’t dissolved in water and Ethanol but in stronger organic compound like Hexane it fully dissolves.

Compounds

Electronic Geometry

Molecular Geometry

Hybridization Polarity

sp ³ Water (H2O)

Tetrahedral

Bent

Polar

sp ³ Ethanol (C2H6O)

Hexane (C6H14)

Observation:

Tetrahedral

NonPolar

Tetrahedral sp ³

Tetrahedral

Tetrahedral

NonPolar

Lewis Structure

During this part of the experiment we worked on establishing the formal charges, electronic geometry, molecular geometry, hybridization, polarity on Lewis Structure of several chemical compounds. We studied the electronic, molecular hybridization and polarity of these solvent and through their Lewis structure where able to find each of their polarities.

Conclusion: The goal of this experiment was to help us furthering our knowledge on how chemical and physical properties of a compound can be determined and highlighted through these steps: Lewis structure, Electronic and Molecular geometry, Polarity and, Intermolecular forces....