How many molecules of ammonia are contained in 10.4 moles of ammonia, NH3? O 0.611 molecules NH3
O 6.26 x 1024 molecules NH3
O 1.71 x 10-23 molecules NH3
O 177 molecules NH3

(C). 1.71× 10-23 molecules NH3

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.