How many of the following IUPAC names are correct___

1) 3-Butanol   2) 2-Butanone  3) 1,2,3-propanetricarboxcylic acid

4) 4-formyl-2-pentanone           5) 2-ethyl-3-methyl hexane

6) 4-Hydroxypentanoic acid      7) 4,4-Dimethylhexanal

1) Should be 1-Butanol

2) Numbering is not necessary

3) Three chain terminating groups ( carret)

4) Aldehyde group is the main functional group

5) ethyl group on the second carbon should be included in the   Carbon chain

6)  correct

7)  correct