chem test 1 multiple choice

when NaCl dissolves in water, aqueous Na+ and Cl- ions result. the force of attraction that exists between Na+ H2O is called ---- a. dipole-dipole b. ion-ion c. hydrogen bonding d. ion-dipole e. London dispersion force

d. ion-dipole

enough of a volatile liquid is placed in a closed container to achieve a liquid vapor equilibrium at a fixed temperature. which of the following statements regarding this system is/are correct once equilibrium is established? 1. liquid molecules are no longer evaporating 2. the number of vapor molecules remains essentially constant 3. the partial pressure exerted by the vapor molecules is called the vapor pressure of the liquid.

2 and 3 only

for which molecule or ion does the nitrogen atom have the positive end of the dipole moment? A. NH4+ B. CN- C. NO D. HCN E. N2

C. NO

the ease with which the charge distribution in a molecule can be distorted by an external electrical field is called the ----- A. electronegativity B. hydrogen bonding C. Polarizability D. Volatility E. viscosity

C. Polarizability

a pi bond is the result of the ----- A. overlap of two s orbitals B. overlap of two p orbitals along their axes C. sideways overlap of two parallel p orbitals D. overlap of an s orbital and a p orbital E. sideways overlap of two s orbitals

C. sideways overlap of two parallel p orbitals

in which of the following molecules is hydrogen bonding likely to be the most significant component pf the total intermolecular forces? A. CH4 B. C5H11OH C. C6H13NH2 D. CH3OH E. CO2

D. CH3OH

which of the following gases would have the highest average molecular speed at 25 degrees Celsius? A. O2 B. N2 C. CO2 D. CH4 E. SF6

D. CH4

which of the following pure substances has the highest normal boiling point? A. H2O B. CF4 C. CsF D. CaF2 E.KF

D. CaF2

which of the following molecules is polar? A. C2H4 B. CS2 C. C6H6 D. SO2 E. CF4

D. SO2

For a substitutional alloy to form, the two metals combined must have similar--- A. ionization potential and electron affinity B. number of valence electrons and electronegativity C. reduction potential and size D. atomic radii and chemical bonding properties E. band gap and reactivity

D. atomic radii and chemical bonding properties

molecular orbital theory correctly predicts paramagnetism of oxygen gas, O2. this is because A. the bond order in O2 can be shown to be equal to 2 B. there are more electrons in the bonding orbitals than in the antibonding orbitals C. the energy of the pi2p MOs is higher than that of the sigma2p MO D. there are two unpaired electrons in the MO electron configuration of O2 E. the O-O bond distance is relatively shorter

D. there are two unpaired electrons in the MO electron configuration of O2

the kinetic molecular theory predicts that pressure rises as the temperature of a gas increases because---- A. the average kinetic energy of the gas molecules decreases B. the gas molecules collide more frequently with the wall C. the gas molecules collide less frequently with the wall D. the gas molecules collide more energetically with the wall E. both the gas molecules collide more frequently with the wall and the gas molecules collide more energetically with the wall

E. both the gas molecules collide more frequently with the wall and the gas molecules collide more energetically with the wall

which of the following molecules has hydrogen bonding as its only intermolecular force? A. HF B. H2O C. C6H13NH2 D. C5H11OH E. none, All the above exhibit dispersion forces

E. none, All the above exhibit dispersion forces

According to MO theory, an overlap of two s atomic orbitals produces ________ A. one bonding molecular orbital and one hybrid orbital B. two boning molecular orbitals C. two bonding molecular orbitals and two antibonding molecular orbitals D. two bonding molecular orbitals and one antibonding molecular orbital E. one bonding molecular orbital and one antibonding molecular orbital

E. one bonding molecular orbital and one antibonding molecular orbital

if more ice is added to an ice water mixture at equilibrium, A. the temp will increase somewhat B. the vapor pressure of the water will decrease C. the temp will decrease somewhat D. the vapor pressure of the water will rise E. the vapor pressure of the water will remain constant

E. the vapor pressure of the water will remain constant

which property of metals cannot be explained with the electron-sea model? A. shine B. high thermal conductivity C. high electric conductivity D. malleability E. trends in melting point

E. trends in melting point

a gas is ------ and assumes ----- of its container, whereas a liquid is ----- and assumes ------ of its container. A. compressible, the volume and shape, not compressible, the shape of the portion B. compressible, the shape, not compressible, the volume and shape C. compressible, the volume and shape, compressible, the volume D. condensed, the volume and shape, condensed, the volume and shape E. condensed, the shape, compressible, the volume and shape

A. compressible, the volume and shape, not compressible, the shape of the portion

a low Melting solid readily dissolves in water to give a nonconducting solution. the solid is most likely a ---- A. molecular solid B. ionic solid C. covalent network solid D. weak base E. metallic solid

A. molecular solid

which of the following is a molecular solid? A. NaCl B. CH4 C. SiO2 D. graphite E. diamond

B. CH4

which of the following molecules in non polar? A. SF4 B. PF5 C. CIF3 D. PF3 E. CH2F2

B. PF5

one significant difference between gases and liquids is that ________ A. a gas is made up of molecules B. a gas expands to fill its container C. a gas may consist of both elements and compounds D. gases are always mixtures E. all of the above

B. a gas expands to fill its container

The heat of sublimation can be approximated by adding together

B. heat of fusion and heat of vaporization