Worksheet 1C: Percent Mass, Moles, and Avogadros Number
- Page ID
- 36935
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1. Calculate each of the following quantities
- Mass in grams of 0.523 moles of \(KCl\)
- Moles of Oxygen atoms in 12.7 g of \(Ba(NO_3)_2\)
- Number of nitrogen atoms in 92.6 g of \(NH_4NO_2\)
- Mass of \(2.04 \times 10^{21}\) molecules of dinitrogen pentoxide
- Number of lithium ions, sulfate, ions, S atoms, and O atoms in 56.2 g of lithium sulfate
2. Calculate the percent by mass of the following compounds
- \(SO_3\)
- \(Pb(SO_4)_2\)
3. Determine the empirical and molecular formulas of each of the following substances:
- Styrene contains 92.3% C and 7.7% H by mass and a molar mass of 104 g/mol
- Caffeine contains 49.5% C, 5.15% H, 28.9% N, and 16.5% O by mass and has a molar mass of 195 g/mol
- Monosodium glutamate contains 35.51% C, 4.77% H, 37.85% O, 8.29% N, and 13.60% Na, and has a molar mass of 169 g/mol.
4. Ethylene glycol
Ethylene glycol is used as an automobile antifreeze and in the manufacture of polyester fibers. Combustion of 6.38 g of ethylene glycol gives 9.06 g \(CO_2\) and 5.58 g \(H_2O\). The compound contains only \(C\), \(H\), and \(O\). What is the empirical formula of the compound?