Pangea was formed in the Paleozoic Era
Moles are used conveniently in chemistry especially in stoichiometric calculations involving reactions. The unit of mole is a collective term that holds 6.022×10^23 particles. These particles is a general term for any small units of matter including molecules, atoms and sub-particles. This ratio of 6.022×10^23 particles to 1 mole is known to be the Avogadro's number. Its exact number is actually <span>6.0221409</span>×10^23. We use this constant in our stoichiometric calculation as follows:
15 moles oxygen * (6.022×10^23 molecules/ 1 mole oxygen) = 9.033×10^24 molecules of oxygen
First, draw the 2-hexene. Th is is a molecule of six carbons with a double bond in the second carbon:
CH3 - CH = CH2 - CH2 - CH2 - CH3
Secong, put one Br on the second carbon and one Br on the third carbon:
CH3 - CBr = CBr - CH2 - CH2 - CH3
Third, cis means that the two Br are placed in opposed positions, this is drawn with one Br up and the other down. So, you need to represent the position of the Br in the space:
H Br H H H
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H - C - C = C - C - C - C - H
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H Br H H H
The important fact to realize is that the two Br are in opposed sides of the molecule.
