HW 10-4

HW 10-4 > > 1A) Rank IMF’s according to relative strength 1B) What factor can significantly change the relative strength of LDF? 1C) The greater the strength of the intermolecular forces between molecules the the boiling point. > > Hydrogen Bonding Dipole- Dipole LDF SIZE OF ELECTRON CLOUD; LARGER CLOUD = STRONG LDF HIGHER

HW 10-4, #2 – Strongest IMF – flow chart YES; ANS = HYDROGEN BOND Is there a hydrogen bond? (H and HFON) NO Do BOTH molecules have a net dipole? YES; ANS = DIPOLE-DIPOLE NO; ANS = LDF

HW 10-4, #2 – Strongest IMF LDF; H2 is nonpolar (no FON to H-bond) A) H2 and H2O B) NH3 and H2O LDF; H2 is nonpolar (no FON to H-bond) HYDROGEN BONDING ; BOTH HAVE HFON

HW 10-4, #2 – Strongest IMF C) BH2F and BH2F

HW 10-4, #2 – Strongest IMF C) BH2F and BH2F DIPOLE- DIPOLE

HW 10-4, #2 – Strongest IMF D) BF3 and BF3 LDF; BF3 is nonpolar (no H to H-bond); symmetric trigonal planar structure

HW 10-4, #2 – Strongest IMF LDF; Both are nonpolar E) NH3 and CH3OH F) He and CH4 HYDROGEN BONDING ; BOTH HAVE HFON

HW 10-4, #3 – Explain Observations in terms of IMF’s A) I2 has a higher boiling point than Br2. Strongest type of IMF between I2 molecules: Strongest type of IMF between Br2 molecules: Explanation: LDF; nonpolar LDF; nonpolar Both are LDF; however strength of LDF depends on size of e- cloud. I2 is farther down family; extra electron levels = bigger atom and stronger LDF

HW 10-4, #3 – Explain Observations in terms of IMF’s B) H2O has a higher boiling point than H2S. Strongest type of IMF between H2O molecules: Strongest type of IMF between H2S molecules: Explanation:

HW 10-4, #3 – Explain Observations in terms of IMF’s B) H2O has a higher boiling point than H2S. Strongest type of IMF between H2O molecules: Strongest type of IMF between H2S molecules: Explanation: Hydrogen bonding; Dipole-dipole Hydrogen bonding is stronger than dipole-dipole H-O is more polar than H-S bond

HW 10-4, #4 – Rank from highest to lowest bp based on IMF’s LDF; nonpolar Strongest type of IMF between H2 molecules: Strongest type of IMF between HF molecules: Strongest type of IMF between HCl molecules: Hydrogen bonding; Dipole-dipole HF > HCl > H2