Why is the H-F bond so much stronger than the H-I bond?
A) H-F is a stronger bond because hydrogen and fluorine are more similar in nature than hydrogen and iodine. Both hydrogen and fluorine are diatomic and gases at room temperature.
B) H-F is stronger bond because iodine forms a solid at room temperature and fluorine forms a gas. Also, iodine tends to sublime at room temperature.
C) H-F is stronger because the fluorine atom is smaller and closer to the hydrogen atom causing greater attraction.
D) Actually, H-I is stronger because the electronegativity of the iodine atom is smaller that that of the fluorine atom.
Question 2
Why can you determine wind direction by wetting your finger and holding it up in the air?
A) Wind carries water molecules, so you can sense the water molecules condensing on the side of your finger that faces the wind.
B) The wind hitting your finger cools the water down, slowing down evaporation. So the cooler side of your finger is windward.
C) When a wet finger is held to the wind, evaporation is greatest on the windy side, which feels cool. The cool side of your finger is windward.
D) Wind direction cannot be determined by wetting your finger because evaporation will occur evenly over the wetted finger.
Directionality of the hydrogen bond
The hydrolysis of an amide bond, shown here, is the same reaction
Formation of phosphodiester bond
Hydrogen bond
Peptide bond as resonance hybrid of two forms
Catalysis of peptide bond hydrolysis by chymotrypsin (part 2)