GenChem2 - Module 1: Molecule Polarity

From 0, state the type of molecule/s given its EN difference.

0.0 = covalent/non-polar < 0.4 < polar < 1.7 < ionic

What condition must be met if a molecule having polar bonds is to be nonpolar?

All charge vectors must cancel out; ie. the moelcule must be symetrical.

Which formula represents a nonpolar molecule? (HBr, H2S, CBr4, PCl3)

CBr4

True or False: A molecule containing polar covalent bonds is always polar.

False

Which of the following molecules, based on the elements present, would be the most polar? (HF, H2, HCl, HBr)

H2

Which of the following is a polar molecule? CH4, Xe, H2O, CO2

H2O

Compare the solubilities of iodine solid (I2) and glucose (C6H12O6) in water, based on their molecular polarities.

Iodine solid will not dissolve in water, while glucose will, since iodine is nonpolar and glucose is polar.

How do we indicate a bond dipole when we draw the structure of a molecule?

The letter 'sigma' with a positive or negative sign.

Explain the polarity of the ff: (geom, polarity) a) SF6 b) SO2 c) BrCl d) AsH3 e) CF2Cl2

a) non-polar b) Bent polar c) Linear polar d) Trigonal pyramidal polar e) Depends upon structural arrangement

Arrange the following molecules in order of probable increasing polarity: a) IBr b) HI c) I2

c,a,b

Which statement correctly describes NaCl? a. Its charge is distributed evenly. b. It is a polar molecule. c. It is ionic, and its charges are distributed very unevenly. d. It contains polar covalent bonds.

c.

Would you expect the molecule SO3 to be polar or nonpolar?

non-polar (trigonal planar )

Would you expect the molecule HCN to be polar or nonpolar?

polar (linear)

Would we expect the molecule PCl3 to be polar or nonpolar?

polar (trigonal pyramidal)

What is the polarity of IBr3 and why?

polar due to its asymmetric geometry

How should the geometry of a molecule look like for it to be polar or nonpolar?

polar: asymmetric

What are the polarity conditions of diatomic molecules?

polar: with polar bond non-polar: same element or w/ non-polar bond

What describes the distribution of charges and the molecular polarity of ethane?

symmetrical and nonpolar

What molecular geometries could be nonpolar?

symmetrical linear, linear with nonpolar bonds, tetrahedral, trigonal planar

What describes the charge distribution and molecular polarity of NH3?

uneven distribution and polar