The energy difference between a tert-butyl group going from equatorial to axial in a cyclohexane is 18.3 kJ/mol. When two of the carbon atoms are replaced with oxygen atoms (molecule B) the energy difference between the two chair conformations drops to 5.9 kJ/mol. Explain this difference. (Hint: Consider what makes putting groups axial unfavorable).

Complete the table for ion charge based upon their losing or gaining electrons in the outer shell. (use the periodic table as necessary.) group most likely ionic charge # of valence electrons i +1 ii +2 iii +3 iv +4 or -4 v -3 vi -2 vii -1 viii 0

The balanced chemical equation for this lab is: 3cucl2(aq) + 2al(s) 3cu(s) + 2alcl3(aq) if 10.5 g copper chloride react with 12.4 g aluminum, what is the limiting reactant?

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely.analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?