Determine the electron geometry, molecular geometry, and idealized bond angles for each molecule. in which cases do you expect deviations from the idealized bond angle? b. nf a. cf4 d. h2s c. of2 which species has the smaller bond angle, h3o or h2o? explain. explain why co2 and cc14 are both nonpolar even though they contain polar bonds. ch& f is a polar molecule, even though the tetrahedral geometry often leads to nonpolar molecules. explain.

The electron geometry, molecular geometry and idealized bond angles for these molecules respectively are:

a. CF4: tetrahedral, tetrahedral and 109.5 degrees

b. NF3 tetrahedral, trigonal pyramidal and 102.5 degrees

c. OF2 tetrahedral, angular and 103 degrees

d. H2S tetrahedral, angular and 92.1 degrees

Explanation:

The electron geometry considers the bound atoms and unbound electron pairs to determine the geometry. The four molecules have four bound atoms and/or unbound electrons pairs, thus they have a tetrahedral geometry. On the other hand, the molecular geometry only considers the position of bound atoms to determine the geometry.

Between H3O and H2O, H2O has a smaller bond angle due to the two unbound electron pairs. The bond angle decrease as the number of unbound electron pairs increases in every molecule.

CO2 and CCl4 are both nonpolar because of the 3D geometry of the molecule. Each individual bond is polar but both molecules have symmetrical geometry so the dipole bonds are canceled.

CH3F  is a polar molecule because the dipole between the C-H and C-F bonds are differents thus, besides the symmetrical geometry the dipole bonds are not canceled.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g