AP CHEMISTRY UNIT 4 - liquid?: A very low vapor pressure 2. The compo...

AP CHEMISTRY UNIT 4

• Which of the following indicates very strong intermolecular forces of attraction in a

liquid?: A very low vapor pressure

• The compounds Br2 and ICl have almost identical molecular weights, yet ICl boils at 97

C and Br2 boils at 59 C. The best explanation for the difference is: ICl has a measurable dipole moment (is polar) and Br2 does not (is non-polar)

• In general, ions which have will form the

strongest interactions with water molecules in aqueous solution.: large charge and small size

• Which compound is most likely to form intermolecular hydrogen bonds? CH4, NaH,

C2H5SH, C2H5OH: C2H5OH

• White powder A melts in a bunsen burner flame, dissolves in water, does not conduct

electricity as a solid, but conducts when dissolved. White powder B also melts in a bunsen burner flame and dissolves in water, but does not conduct electricity either as a solid or in solution. The solid types represented by samples A and B are probably:: A = ionic, B = molecular

• Paper chromatography was used to separate the dyes within marker ink. The dye that

traveled the farthest up the paper (had the greatest Rf value) must have had:: The highest affinity for the mobile phase only

• An unknown substance does no dissolve in water, does not conduct electricity or melt in

a bunsen burner flame. It is extremely hard and resists efforts to be ground into a powder using a ceramic mortar and pestle. One could surmise that the substances is probably a

solid.: Net- work-covalent

• Spring steel is harder and stronger than pure iron metal by itself. The best explanation for

this would be:: The extra bonds provided by the interstitial component causes the metal lattice to become harder, stronger, and less ductile.

• Which would be the best choice to use for n-type doping of a silicon semiconductor?: P -

Phosphorus

• Of the following gases, which one will have the greatest rate of effusion at a given

temperature? NH3, CH4, Ar, HBr, HCl: CH4

• Arrange the following gases in order of increasing average molecular speed at 25 C. Cl2,

O2, F2, N2: Cl2, F2, O2, N2

• Liquid nitrogen has a boiling point of -196 C, this corresponds to... Kelvin: 77 K
• For an ideal gas, which pair of variables are inversely proportional to each other?: P, V
• A given mass of gas in a rigid container is heated from 100 C to 300 C. Which of the

following best describes what will happen to the pressure of the gas? The pressure will...: increase by a factor less than three.

• Substance A condenses in the highest portion of the column (the coolest temperature),
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