Find the percent of water in Zn3(PO4)2 x 7H2O

24.66%

Explanation:

To find the percent of water (H2O) in the following compound: Zn3(PO4)2. 7H2O

The atomic mass of the elements are as follows:

Zn = 65g/mol

P = 31g/mol

O = 16g/mol

H = 1g/mol

Hence, molar mass of the compound is as follows:

65(3) + {31 + 16(4)} 2 + 7{1(2) + 16}

195 + 95(2) + 7(18)

195 + 190 + 126

511g/mol

Molar mass of 7H2O

= 7(18)

= 126g/mol

Hence, the percent of H2O in the compound is:

Molar Mass of 7H2O/molar mass of compound × 100

= 126/511 × 100

= 0.2466 × 100

= 24.66%

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.

gasoline is a mixture. it contains several different kinds of compounds that can be present in a variety of ratios.