91Ó°ÊÓ

A sample of ammonia, \(\mathrm{NH}_{3}\), contains \(3.3 \times 10^{21}\) hydrogen atoms. How many \(\mathrm{NH}_{3}\) molecules are in this sample?

A sample of ethanol (ethyl alcohol), \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\), contains \(4.2 \times 10^{23}\) hydrogen atoms. How many \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\) molecules are in this sample?

Iron(II) nitrate has the formula \(\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{2}\). What is the ratio of iron atoms to oxygen atoms in this compound?

Ammonium phosphate, \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\), has how many hydrogen atoms for each oxygen atom?

Write the formula for the compoun following pairs of ions. a. \(\mathrm{Fe}^{3+}\) and \(\mathrm{CN}^{-}\) b. \(\mathrm{K}^{+}\) and \(\mathrm{SO}_{4}^{2-}\) \(\pm\) 3

For each of the following pairs of ions, write the formula of the corresponding compound. a. \(\mathrm{Co}^{2+}\) and \(\mathrm{Br}^{-}\) b. \(\mathrm{NH}_{4}{ }^{+}\) and \(\mathrm{SO}_{4}^{2-}\) c. \(\mathrm{Na}^{+}\) and \(\mathrm{PO}_{4}{ }^{3-}\) d. \(\mathrm{Fe}^{3+}\) and \(\mathrm{NO}_{3}^{-}\)

Name the following compounds. a. \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) b. \(\mathrm{CaS}\) c. \(\mathrm{CuCl}\) d. \(\mathrm{Cr}_{2} \mathrm{O}_{3}\)

Name the following compounds. a. \(\mathrm{Na}_{2} \mathrm{O}\) b. \(\mathrm{Mn}_{2} \mathrm{O}_{3}\) c. \(\mathrm{NH}_{4} \mathrm{HCO}_{3}\) d. \(\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}\)

Write the formulas of: a. lead(II) permanganate b. barium hydrogen carbonate c. cesium sulfide d. iron(II) acetate

Write the formulas of: a. sodium thiosulfate b. copper(I) hydroxide c. calcium hydrogen carbonate d. nickel(II) phosphide