CHEM 107 MIDTERM

which of the following aqueous solutions has the highest boiling point (assume 100% dissociation for all soluble ionic compounds)? a)0.18m NaCl b)0.10m Al(NO3)3 c)0.11m Na2SO4 d)0.35m C6H12O6 e)0.15m K2CO3

0.15m K2CO3

which of the following solutions has the lowest osmotic pressure? a)0.20M NH3 b)0.10M Al(NO3)3 c)0.10M MgCl2 d)0.15M Ba(NO3)2 e)0.15M NaCl

0.20M NH3

which of the following corresponds to the correct integrated expression for a second-order reaction? a)1/A0 - KT=A b)ln A0/A=KT c)1/A - 1/A0=KT d)1/A - 1/B=KT e)1/A0 - ln A/A0=KT

1/A - 1/A0=KT

The activation energy for a reaction can be changed by 1.adding more reactants 2.adding a catalyst 3.providing another reaction pathway a)3 only b)2 and 3 only c)2 only d)1 only e)1 and 2 only

2 and 3 only adding a catalyst providing another reaction pathway

A solution of chloroform, CHCl3, and acetone, (CH3)2CO, exhibits a negative deviation from Raoult's law. This result implies that a)chloroform-chloroform interactions are stronger than chloroform-acetone interactions. b)chloroform-chloroform interactions are weaker than chloroform-acetone interactions c)acetone-acetone interactions are stronger than chloroform-acetone interactions d)acetone-acetone interactions are weaker than chloroform-acetone interactions e)both B and D f)Both A and C

Both B and D chloroform-chloroform interactions are weaker than chloroform-acetone interactions. acetone-acetone interactions are weaker than chloroform-acetone interactions.

which of the following substances is expected to have the lowest melting point? a)NaI b)BrI c)CsI d)RbI e)LiI

BrI

which of the following substances is expected to have the highest molar heat of vaporization? a)He b)H2O c)C6H6 d)Ar E)NH3

H2O

which one of the following substances will have both dispersion forces and dipole-dipole forces? a)CO2 b)HCl c)H2 d)BCl3 e)Br2

HCl

which one of the following substances is expected to have the highest boiling point? a)HF b)HI c)HCl d)HBr

HF

Arrange the following substances in order of increasing boiling point: CH3OH, He, CH3Cl, N2 a)He<N2<CHCl<CH3OH b)N2<He<CH3OH<CH3Cl c)CH3OH<He<CH3Cl<N2 d)CH3Cl<He<N2<CH3OH e)He<N2<CH3OH<CH3Cl

He<N2<CH3Cl<CH3OH

which one of the following substances is expected to have the highest boiling point? a)F2 b)Br2 c)I2 d)Cl2

I2

which of the following gases is expected to have a higher solubility in water than what is predicted using henry's law? a)Ar b)NH3 c)H2 d)N2 e)CH4

NH3

which one of the following substances should exhibit hydrogen bonding in the liquid state? a)H2S b)CH4 c)H2 d)NH3 e)PH3

NH3

Which of the following characteristics indicates the presence of weak intermolecular forces in a liquid? A)high critical temperature B)high boiling point C)a low heat of vaporization D)a low vapor pressure E)none of above

a low heat of vaporization

Which of the following properties indicates the presence of strong intermolecular forces in a liquid? a) a low vapor pressure b) a low heat of vaporization c) a low boiling point d) a low critical temperature e) none of the above

a low vapor pressure

Dipole-induced dipole

a polar molecule and nonpolar molecule (HCl and Cl2)

which of the following would be expected to have the highest vapor pressure at room temperature? a)methanol,bp=65 b)water,bp=100 c)acetone,bp=56 d)ethanol,bp=78

acetone,bp=56

for which order reaction is the half-life of the reaction proportional to the 1/k (k is the rate constant)? a)second-order reaction only b)zero-order reaction only c) first-order reaction only d)all the above e)none of above

all the above

Ion-induced dipole

an ion and a nonpolar (HCl,Cl2)

ion-dipole

an ion and polar molecule (Na+, H2O)

Which of the following statements is consistent with Boyle's Law concerning an ideal gas? a)at constant temperature and moles, a plot of pressure versus the inverse of volume is linear. b)At constant pressure and moles, a plot of temperature versus volume is linear c)At constant temperature and moles, a plot of volume versus pressure is linear d)at constant temperature and pressure, a plot of moles versus volume is linear e)At constant pressure and volume, a plot of temperature versus moles is linear

at constant temperature and moles, a plot of pressure versus the inverse of volume is linear

which of the following phase changes is exothermic? a)vaporization b)sublimation c)condensation d)melting

condensation

the solubility of gases in water usually increases with a)increasing temperature and decreasing pressure b)decreasing temperature and increasing pressure c)decreasing temperature and decreasing pressure d)increasing temperature only e)increasing pressure and increasing temperature

decreasing temperature and increasing pressure

A phase change from the gas phase directly to the solid phase is called: a)melting b)sublimation c)condensation d)deposition e)freezing

deposition

hydrogen bonding

molecules which have H on N,O, or F atoms

During osmosis a)gases diffuse through a membrane into a solution and build up pressure. b)pure solvent diffuses through a membrane but solutes do not. c)pure solutes diffuse through a membrane but solvent does not. d)pure solvent and a solution both diffuse at the same time through a membrane.

pure solvent diffuses through a membrane but solutes do not.

The reaction A->products is first-order in A. If the concentration of A is cut in half, the half-life of the reaction will a)decrease by a factor of 1/2 b)decrease by a factor of 1/4 c) quadruple d)duble e)remain constant

remain constant

which of the following phase changes is endothermic? a)deposition b)freezing c)sublimation d)condensation

sublimation

which property of water allows a razor blade to float on it without sinking? a)surface tension b)specific heat c)triple point d)density e)viscosity

surface tension

the potential-energy diagram below describes the hypothetical reaction A+B->C + D Which of the following statements is corect? a)the forward reaction is endothermic b)the activation energy for the forward reaction is greater than that for the reverse reaction c)the effect of a temperature change is greater for the reverse reaction than for the forward reaction d)the activation energy for the reverse reaction is less than zero e)A and B are lower in energy than C and D

the effect of a temperature change is greater than that for the reverse reaction.

Based on the phase diagram shown below, how will the melting point of the substance change if the pressure is increased above 1 atm? a)the melting point will remain the same b)the melting point will increase c)the substance will not melt at pressures of 1 atm and above; instead, the solid sublimes to form the gas phase d)the melting point will decrease

the melting point will increase

the vapor pressure of a liquid in a closed container depends upon a) surface area of a liquid b)the temperature c)the amount of liquid d)the volume of container e)none of above

the temperature

according to Raoult's law, which statement is false? a)the solubility of a gas increases as temperature decreases b)the greater the pressure of gas over a solution the greater its solubility c)the vapor pressure of a solvent over a solution decreases as its mole fraction increases. d)Ionic solutes dissociate in solution causing an enhancement of all colligative properties. e)the vapor pressure of a solvent ver a solution is less than that of pure solvent

the vapor pressure of a solvent over a solution decreases as its mole fraction increases.

according to VSEPR theory, the geometry of the SO3 molecule is a)trigonal planar b)square planar c)tetrahedral d)pyramidal E)distorted tetrahedron

trigonal planar

Dispersion forces

two nonpolar molecules all molecules have this

Dipole-dipole

two polar molecules

a liquid boils when its a)temperature is equal to 273K b)temperature is greater than room temperature c)vapor pressure is equal to, or greater than, the external pressure pushing on it d)vapor pressure is exactly 1 atmosphere

vapor pressure is equal to, or greater than, the external pressure pushing on it

which of the following would be expected to have the lowest vapor pressure at room temperature? a)methanol,bp=65 b)acetone,bp=56 c)ethanol,bp=78 d)water,bp=100

water,bp=100