Chem 2 Sample Test

POSSIBLE USEFUL ITEMS:

R = 0.08206 atm • L/(mol • K) = 8.314 J/(mol•K) or J/K

EVP of H2O Freezing point ∆Tf = Kf x m

Heat capacity equation q = ∆T x mass C

Gas solubility equation [X(aq)] = kH x P

OsmoticPressure π = M x R x T

1. (20 pts) Indicate whether each statement is true (T) or false (F). Write legibly.

____EVP is the pressure of a gas phase component in equilibrium with its liquid or solid phase

____Weaker intermolecular forces give a lower EVP.

_____The sign of ∆S° for every sublimation reaction is positive

____The sum of ∆H°sub + ∆H°fus is ∆H°vap.

____Soft atoms are easily polarizable

____Orientation effects are greater for hydrogen bonding than for dispersion.

____An induced dipole is a type of temporary dipole.

____ Carbon atoms are too hard to provide any dispersion.

____Glucose (C6H12O6) is soluble in water due to entropy.

____Cohesion & adhesion are two attractions which result in the surface tension of a liquid

2. (5 pts) Consider urea, (NH2)2CO(s), dissolving in water.

______ Is ∆H°soln positive or negative?

______Is ∆S°soln positive or negative

______Is (NH2)2CO(s) miscible, soluble (but not miscible) or insoluble in water

(13 pts.) List the five intermolecular forces that might occur in mixtures

1. 4.

2.

5.

.

Which forces oppose vaporization of SiCl4?

Of the five major types of crystalline solids, which type is formed by SF6?

Between O2- and F–, which ion has the larger (more negative) ∆H°hydr?

4. (6 pts.) List the intermolecular force(s) which operate in each of the following pure compounds. If more than one is operating, CIRCLE the STRONGEST for that compound.

SO3 __________________________________________________________________________________________

NI3 __________________________________________________________________________________________

AsH3...