Chem 202 Exam 2 with Questions and Answers

Chem 202 Exam 2 with Questions and
Answers
which substances exhibit only london (dispersion) forces? ANSWER Cl2 and He



if a solid line represents a covalent bond and a dotted line represents intermolecular
attraction, which of the choices shows a hydrogen bond? ANSWER H3N⋅⋅⋅⋅⋅⋅H−O−H



Arrange the molecules from strongest london (dispersion) force to weakest ANSWER
1.CH3CH2CH2CH2CH2CH2CH3



2.CH3CH2CH2CH2CH3



3.CH3C(CH3)2CH3



Hydrogen bonding, dipole-dipole, and dispersion ANSWER H2O



Dipole-dipole and dispersion only ANSWER CH3Cl and CO



Dispersion only ANSWER H2



Arrange these compounds by their expected boiling point (highest and lowest). ANSWER 1.
CH3OH

2. CH3Cl

3. CH4



strong intermolecular forces ANSWER - high boiling point

, - high surface tension



- high viscosity



weak intermolecular forces ANSWER high vapor pressure



body centered cubic ANSWER - 8 corners

- 1 body atom

- 1/8 fraction of each corner atom inside the boundaries of the cube

- 2 total number of atoms



8 × (1/8) + 1 = 2 atoms.



ionic solids ANSWER Na2S



molecular solid ANSWER CCl4



metallic solid ANSWER K



covalent solid ANSWER C (diamond)



H2O is a polar molecule which exhibits ANSWER mainly hydrogen bonding



He is nonpolar and so it exhibits ANSWER primarily London forces