Question 1
Isopropanol (Propan-2-ol) is widely used as a disinfectant as well as a solvent, because it mixes well with water as well as heptane. But caution is advised, because it is flammable as well as an irritant.
a) Draw the Lewis structure of the isopropanol molecule (don’t omit lone electron pairs!). Explain the solubility in water as well as heptane using the molecular structure. [6]
b) Compare the solubility of isopropanol to that of propan-1,2-diol as well as that of octan-2-ol. [4]
Question 2
a) Determine whether the following molecules are dipole-molecules or non-polar. Give a reason for your decision. [8]
b) A student from a different school states “There are three types of bonds in molecules. Polar co- valent bonds, non-polar covalent bonds and hydrogen bonds.” Correct the statement. [2]
Question 3
Intermolecular forces always seem to contradict themselves… After looking at the electronegativity ta- ble of his chemistry book, Sean believes that hydrogen fluoride and lithium bromide should have very similar substance properties. But after doing some more research he finds the following data:
Substance Hydrogen flouride Lithium bromide
Melting point -83°C 550°C
Boiling point 19,5°C 1265°C
State of matter at room temperature
gas Solid
Substance category Inorganic molecular substance Ionic compound
Sean was convinced that hydrogen flouride and lithium bromide should have similar properties. Explain why he thought that and name the substance that is not behaving as expected. [3]
2. Kurzarbeit Chemistry – 14.03.2018 Year 10
Topics: Alcohols, Intermolecular forces Time: 30 Minutes
Name: ______________________ Grade:
