How many moles of hydrogen gas are produced when 0.4 moles of sodium react with excess water? 2Na + 2H2O -> 2NaOH +H2

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong

i believe it is c.) 1575 j.

there is none because earth is stationary and flat.

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.