Exam 3

VSPER

100

Identify the electron geometry of NH₂^-

Tetrahedral

200

Identify the molecular geometry of PF₅

Trigonal Bipyramidal

300

Identify both the electron and molecular geometry of SF₄

Electron is trigonal bipyramidal, molecular is seesaw

400

Identify the electron, molecular geometry and bond angle of ClF₃

Electron is trigonal bipyramidal, molecular is T-shaped

Intermolecular forces

100

Rank the the intermolecular forces based on increasing strength: Hydrogen bonding, dispersion and dipole-dipole

Dispersion < Dipole-dipole < Hydrogen

200

Identify the type of intermolecular force in NH₃

Hydrogen Bonding

300

Rank the following molecules from weakest to strongest intermolecular forces: HCl, H₂,  H₂O and CH₃OH

H₂ < HCl < CH₃OH < H₂O

400

Arrange the following molecules in order of increasing boiling point: CH₃CH₂OH, CH₃OH, CH₄, CH₃CH₃

CH₄ < CH₃CH₃ < CH₃OH < CH₃CH₂OH

Work and Heat

100

A gas expands from 10.0 L to 20.0 L at a constant pressure of 2 atm. Calculate the work done by the gas in both L·atm

-20 L·atm

200

A 75 g piece of metal is heated from 20°C to 100°C by absorbing 1500 J of heat. What is the specific heat capacity of the metal?

0.25 J/C

300

A gas does 300 J of work on its surroundings by expanding against a constant external pressure of 1.2 atm. If the initial volume is 4.0 L, what is the final volume of the gas? (Note: 1 L·atm = 101.3 J)

6.47 J

400

A 300 g sample of a metal absorbs 4500 calories of heat, causing its temperature to rise from 25°C to 75°C. What is the specific heat capacity of the metal in J/g°C? (Note: 1 calorie = 4.184 joules)

1.2552 J/C

Hybridization/sigma and pi bonds

100

How many sigma and pi bonds are in the a double bond and triple bond

Double is one sigma and one pi bond

Triple is one sigma and two pi bonds

200

Determine the hybridization of BeCl₂

sp

300

Determine the hybridization of PCl₅

sp³d

400

Determine the hybridization and amount of sigma and pi bonds in NO₃^-

hybridization is sp², has 3 sigma bonds, one pi bond

Miscellaneous

100

Define exothermic and endothermic

Endothermic is when heat is absorbed, exothermic is when heat is released

200

Determine what occurs to ΔE when Q is negative and W is negative

Energy is released

300

Define intermolecular forces and intramolecular forces

Intermolecular forces is between molecules and intramolecular forces is found within a molecule

400

Determine what occurs to ΔE and identify what Q and W indicate: Q is negative and w is positive

Q = heat is released, W = work is done on ΔE = depends on the sizes of q and w