Consider the following balanced chemical reaction: 2Na + Cl2 --> 2NaCl
How many grams of NaCl are produced from 4.5 grams of CI2
0.75 grams NaCl
0.83 grams NaCl
1.85 grams NaCl
7.5 grams NaCl

i believe the answer is 5,000

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".

5 structural isomers

the isomers are:

n-exane :   ch3ch2ch2ch2ch2ch3

2-methylpentane :   ch3ch(ch3)ch2ch2ch3

3-methylpentane :   ch3ch2ch(ch3)ch2ch3

2,3-dimethylbutane :   (ch3)2chch(ch3)2

2,2-dimethylbutane :   (ch3)3cch2ch3