Carbon dioxide CO2 is a gas at room temperature. Carbon diselenide CSe2 is a liq
ID: 494499 • Letter: C
Question
Carbon dioxide CO2 is a gas at room temperature. Carbon diselenide CSe2 is a liquid at room temperature. The normal boiling point is 125 degrees Celcius, and the melting point is -45.5 degrees Celcius. Carbon disulfide (CS2) is also a liquid at room temperature with normal boiling and melting points of 46.5 degrees Celcius and -111.6 degrees Celcius, respectively. How do the strengths of the intermolecular forces vary from CO2 to CS2 to CSe2? Rank in order of INCREASING force, beginning with the weakest. AND which of the following statements best explains the ordering? 1) All three are linear and non-polar; the London forces which hold them together are strongest for the smallest molecule 2) The C-O bond is most polar and the C-Se bond least polar; so the dipole-dipole interactions are strongest for the most polar bond 3) The C-Se bond is most polar and the C-O bond least polar; so the dipole-dipole interactions are strongest for the most polar bond 4) All three are linear and non-polar; the London forces which hold them together are strongest for the largest molecule 5) The hydrogen bonding forces are greatest in CO2 bcause of the smaller and more electronegative O atom.
Explanation / Answer
Solution. Strengths of the intermolecular forces.
CO2 < CS2 <CSe2
Because, All three are linear and non-polar; the London forces which hold them together are strongest for the largest molecule.