Question
Please answer the following questions make sure you round the numbers to the correct sig figs.
What is the principal interparticle force in a sample of each of the following? In each pair, identify all the intermolecular forces, and select the substance with the higher boiling point. What intermolecular forces are present? (Select all that apply.) Which substance has the higher boiling point ? What intermolecular forces are present? Which substance has the higher boiling point ? What intermolecular forces are present? Which substance has the higher boiling point ? The coinage metals - copper, silver, and gold -- crystallize in a cubic closest packed structure. Use the density of copper (8.95 g/cm3) and its molar mass (63.55 g/mol) to calculate an approximate atomic radius for copper. A 0.75 L bottle is cleaned, dried, and closed in a room where the air is 20degreeC and 45% relative humidity (that is, the water vapor in the air is 0.45 of the equilibrium vapor pressure at 20degreeC). The bottle is brought outside and stored at 0.0degreeC. (See Table 5.2) What mass of water condenses inside the bottle? 0.0032 Your response differs from the correct answer by more than 10%. Double check your calculations, g Would water condense at 10degreeC?
Explanation / Answer
Soluiton :
1a : H bonding
1b : dispresion only
1c: H bonding
2) dipole and dispersion
3) H bonding and dispersion
4) H bonding and dispersion
5)
Cubic closest packed structure has packing density of 2
d = ?/(3??2) ? 0.74
That means only 74% of the volume of the crystal lattice are occupied by atoms.
When you divide the molar weight by the density you get volume of crystal lattice per mol of atoms
is the face centered cubic lattice. So one mole atoms is occupy a volume of
(M/?)?d
and a single atom in closed packed structure occupies
V = M?d/(??Na) = ??M/(3??2???Na)
(Na is the Avogadro constant)
Since the atoms are considered as solid spheres of radius r:
(4/3)???r