The Diels Alder reaction is a concerted reaction. Define concerted. The product contains a cyclic ring. The diene must be in the s-cis conformation to react. All changes in bonding (bond making and bond breaking) occur simultaneously. It is an endothermic reaction. Both exo and endo products are formed.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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~ trueboss72

i think that the answer is c