The constant pressure molar heat capacity, C_{p, m}C p, m , of methane gas, CH_4CH 4 , is 35.31\text{ J K}^{-1}\text{ mol}^{-1}35.31 J K −1 mol −1 at temperatures close to 298\text{ K}298 K. Calculate the enthalpy change when 1.6\text{ kg}1.6 kg of methane gas is heated from a temperature of 280\text{ K}280 K to 320\text{ K}320 K.

your answers are a,b,,e and f

i hope this

a electronegativity decreases beacuse the size of nucleus is bigger.

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.