Calculate the mass of hydrazine (n2h4) that contains a billion (1.000 x 10^9) hydrogen atoms.
be sure your answer has a unit symbol if necessary, and round it to 4 significant digits.

1.3285 × 10⁻¹⁴ g of hydrazine

Explanation:

if         32 g of hydrizine (1 mole) contains 4 × 6.022  × 10²³ hydrogen atoms

then     X g of hydrizine contains 1 × 10⁹ hydrogen atoms

X = (32 × 1 × 10⁹) / (4 × 6.022  × 10²³)

X = 1.3285 × 10⁻¹⁴ g of hydrazine

b.

the accuracy of the data.

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.