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Practice 8.4.1 Mole Conversions (one step)
Directions: Answer the following questions. Set-up all problems using the factor-label method of
dimensional analysis and show all your work and units.
1. How many atoms are in 1.5 moles of neon?
2. Calculate the number of moles in 5.45x1025 atoms of Zn?
3. What is the mass of 7.50 moles of sulfur dioxide (SO2)?
4. How many moles are there in 250.0 grams of sodium phosphate (Na3PO4)?
5. What is the volume of 0.38 moles of any gas at STP?
6. Calculate the number of moles in 32.2-L of NH3
Answers: 1) 9.0x1023atoms, 2) 90.5 moles, 3) 481 g, 4) 1.52 g, 5) 8.5 L, 6) 1.44 mol
1.5 mol Ne x 6.02 x 1023 / 1 mol Ne = 9.03 x 1023 atoms Ne
5.45 x 1025 atoms Zn x 1 mol Zn / 6.02 x 1023 = 90.5 mol Zn
7.50 mol SO2 x 64.1 g SO2 / 1 mol SO2 = 481 g SO2
250.0 g Na3PO4 x 1 mol Na3PO4 / 164.0 g Na3PO4 = 1.52 g Na3PO4
0.38 mol gas x 22.4 L gas/ 1 mol gas = 8.5 L gas
32.2 L NH3 x 1 mol NH3 / 22.4 L NH3 = 1.44 mol NH3
