When 64.0 g of methanol (choh) is burned, 1454 kj of energy is produced. what is the heat of combustion for methanol?

 The heat  of combustion  for  methanol   is 727  kj/mol

    calculation

 calculate the moles  of methanol (CH3OH)

moles = mass/molar  mass

molar mass of methanol =  12 +( 1 x3)  +16 + 1= 32 g /mol

moles is therefore= 64.0 g / 32 g/mol =  2 moles

Heat of combustion  is therefore = 1454 Kj / 2 moles =  727  Kj/mol

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.