Question

4. How much energy is needed to convert 64.09 grams of water at 100.°C to steam at 128.40 °C?
specific heat (steam) = 2.09 J/g°C
specific heat (water) = 4.18 J/g°C
heat of fusion = 6.02 kJ/mol
heat of vaporization = 40.6 kJ/mol

144.42 kJ

  

25.21 kJ

  

152.03 kJ

  

3.80 kJ

  

148.23 kJ

5. The charges with sodium chloride are all balanced-for every positive sodium ion there is a corresponding negative chloride ion. Since its charges are balanced, how can sodium chloride be attracted to water, and vice versa?

  

Hydrogen bonding in water allows the sodium chloride molecule to be attracted to the water molecule.

   

As a water molecule gets close to the sodium chloride it can distinguish the various ions and it is thus attracted to an individual ion by ion-dipole forces.

   

Dispersion forces come into play as the sodium chloride and water come into close proximity.

   

This is not a matter of attraction. Sodium chloride dissolves in water because water provides a medium in which the individual sodium and chloride ions can disperse.

6. Which of the following intermolecular forces best describes why nonpolar molecules like gasoline (C₈H₁₈) have only limited solubility in water?

  

dipole-dipole

   

ion-dipole

   

Both dipole-dipole and induced dipole-induced dipole

   

induced dipole-induced dipole

Answer 1

128:4 wabr st mda fuabrx hut ofuaparied 64.01 melx4o.6K 3fnt ДИ, 18 144.5 KJ mcAT 64.093 x 2.orLK 3 8011 -3-8 04 KT 14 4.5t 3-8 Y CT 148.23 KJ