91Ó°ÊÓ

How many moles of calcium (Ca) atoms are in \(77.4 \mathrm{~g}\) of \(\mathrm{Ca} ?\)

How many grams of gold (Au) are there in 15.3 moles of \(\mathrm{Au} ?\)

What is the mass in grams of a single atom of each of the following elements? (a) \(\mathrm{Hg},\) (b) Ne.

What is the mass in grams of a single atom of each of the following elements? (a) As, (b) Ni.

Which of the following has more atoms: \(1.10 \mathrm{~g}\) of hydrogen atoms or \(14.7 \mathrm{~g}\) of chromium atoms?

Which of the following has a greater mass: 2 atoms of lead or \(5.1 \times 10^{-23}\) mole of helium?

Calculate the molecular mass or formula mass (in amu) of each of the following substances: (a) \(\mathrm{CH}_{4}\) (b) \(\mathrm{NO}_{2},(\mathrm{c}) \mathrm{SO}_{3},\) (d) \(\mathrm{C}_{6} \mathrm{H}_{6}\) (e) NaI, (f) \(\mathrm{K}_{2} \mathrm{SO}_{4}\) \((\mathrm{g}) \mathrm{Ca}_{3}\left(\mathrm{PO}_{4}\right)_{2}\)

Calculate the molar mass of the following substances: (a) \(\mathrm{Li}_{2} \mathrm{CO}_{3},\) (b) \(\mathrm{CS}_{2},\) (c) \(\mathrm{CHCl}_{3}\) (chloroform), (d) \(\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{6}\) (ascorbic acid, or vitamin \(\mathrm{C}\) ), (e) \(\mathrm{KNO}_{3},\) (f) \(\mathrm{Mg}_{3} \mathrm{~N}_{2.}\)

Calculate the molar mass of a compound if 0.372 mole of it has a mass of \(152 \mathrm{~g}\).

How many molecules of ethane \(\left(\mathrm{C}_{2} \mathrm{H}_{6}\right)\) are present in \(0.334 \mathrm{~g}\) of \(\mathrm{C}_{2} \mathrm{H}_{6} ?\)