6. What does the following hydrogenation data tell you about 1,3-cyclobutadiene? AH = -129 KJ/mol Miod ldil H (9) Pd/C H (g) Pd/C AH = -400 KJ/mol he which are aromatic, antiaromatic, and 7. Using Hckel's rules, determine which nonaromatic. Ann aroma po e + tic confounds have DO DO De NH