DAT Chemistry

Question 1

VSPER

Name the EDG & MDG:
What is the Bond Angle?
What is the Hybridization?

2 Electron Domain Molecule (3 atoms)

O=C=O

Answer 1

EDG: Linear
MDG: Linear
Bond Angle: 180°
Hybridization: sp

Note: EDG have no line pair of electron on center atom. Only MDG have lone pairs and depending on how many it will change the geometry

Question 2

VSPER

Name the EDG & MDG:
What is the Bond Angle?
What is the Hybridization?

3 Electron Domain Molecule (4 atoms)

Ex. Cl-B-Cl
Cl

Answer 2

EDG: Trigonal Planar
MDG: (0) Trigonal Planar, (1) Bent
Bond Angle: 120°
Hybridization: sp2

Note: EDG have no line pair of electron on center atom. Only MDG have lone pairs and depending on how many it will change the geometry

Question 3

VSPER

Name the EDG & MDG:
What is the Bond Angle?
What is the Hybridization?

4 Electron Domain Molecule (5 atoms)

Answer 3

EDG: Tetrahedral
MDG: (0) Tetrahedral, (1) Trigonal Pyramidal, (2) Bent,
Bond Angle: 109.5°
Hybridization: sp3

Note: EDG have no line pair of electron on center atom. Only MDG have lone pairs and depending on how many it will change the geometry

Question 4

VSPER

Name the EDG & MDG:
What is the Bond Angle?
What is the Hybridization?

5 Electron Domain Molecule (6 atoms)

Answer 4

EDG: Trigonal Bipyramidal
MDG: (0) Trigonal Bipyramidal, (1) See-saw, (2) T-shape, (3) Linear
Bond Angle: 90°, 120° or 180°
Hybridization: sp3d

Note: EDG have no line pair of electron on center atom. Only MDG have lone pairs and depending on how many it will change the geometry

Question 5

VSPER

Name the EDG & MDG:
What is the Bond Angle?
What is the Hybridization?

6 Electron Domain Molecule (7 atoms)

Answer 5

EDG: Octahedral
MDG: (0) Octahedral, (1) Square pyramidal, (2) Square planar
Bond Angle: 90°,
Hybridization: sp3d2

Note: EDG have no line pair of electron on center atom. Only MDG have lone pairs and depending on how many it will change the geometry

Question 6

Phase Transition:

Solid->Liquid-> Gas
Solid->Gas

Answer 6

Solid –Fusion–>Liquid–Vaporization–>Gas
Solid–Sublimation–> Gas

Endothermic Rxn ΔH+, greater than 0
ΔS= greater than 0 (add energy = increase chaos)

Question 7

Phase Transition:

Gas–> Liquid–> Solid
Gas–> Solid

Answer 7

Gas–Condensation–> Liquid–Freezing–> Solid
Gas–Deposition–> Solid

Exothermic Rxn (release heat/energy)
ΔH- less than 0
ΔS less than 0, removing energy lowers chaos

Question 8

Calorimetry Equation

Answer 8

q=mcΔT & nΔH(fusion/vapor, etc)

c= heat capacity
n=moles

Question 9

STP

Answer 9

1 atm=760 torr=760mmHG
Vol= 22.4L
Temp: 0°= 273K

Question 10

Ideal Gas Law

Answer 10

PV=nRT

R= 0.08206 Latm/molK

Question 11

Equation for Partial Pressure

Answer 11

P(a)+P(b)=P(c)= P(total)
P(a)=χ(a)P(total)

χ= chi= mole fraction

Question 12

Graham’s Law of Effusion Equation

Answer 12

r1/r2= SquareRoot M2/M1

Question 13

Avogradros #

Answer 13

6.02x10^23= 1 mol or 1 particle

Question 14

Molarity Equation

Molality Equation

Answer 14

Molarity= mol(solute)/V(solvent in liters)

Molality(m)= mol (solute)/kg(solvent)

Question 15

Mole Fraction equation

Answer 15

X(solvent)= mol (solvent) / mol (total solution)

X(solute+X(solvent)=1

X(solute)=mol (solute) / mol(total solution)

Question 16

Van’t Hoff Factor Equation (B.P, Freezing Pt, Vapor Pressure, Osmotic Pressure)

Answer 16

B.P: ΔT(B.P)= iK(B.P)m

F.P: ΔT(f)= -iK(f)m (-i bc F.P decrease w/add. of particles)

V.P: P(a)= X(a)P(total) same eq. as partial pressure X=mole fraction

O.P: π=iMRT