<p> Chemical Quantities Study Guide Pre-AP-Key</p><p>(Chapter 10 )</p><p>Name:______</p><p>1. Define the following vocabulary words:</p><p> Mole= unit of measurement for tiny particles (atoms, compounds)</p><p> Representative particles: substances that make-up matter (atoms, ionic compounds, molecules (covalent compounds).</p><p> Molar mass= atomic mass of one mole of a substance. </p><p> Percent composition of a compound= percent of mass an element contributes to a compound’s molar mass.</p><p>2. List the three common ways in which matter is measured and give an example of each.</p><p>Mass , quantity, and volume</p><p>3. Name the specific type of representative particle for each substance below.</p><p> a. Al(OH)3 (ionic compound) b. H2C2O4 (molecule/covalent) c. Na (atom) </p><p> d. Fe3P2 (ionic compound) e. H2O (molecule/covalent)</p><p>4. Identify the conversion needed to convert between these units of measurement.</p><p> a. moles and representative particles : 1 mole of a substance = 6.02x1023 particles of that substance</p><p> b. moles and mass of a substance: 1 mole of a substance = the molar mass of that substance</p><p>5. How many atoms of Sn are in 3.0 moles of Sn ? (mole-particles conversion)</p><p>=1.8x1024 atoms of Sn (2 significant figures)</p><p>6. How many moles of KCl are in 1.35x1021 compounds of KCl ? </p><p>= 0.00224 moles of KCl (3 significant figures)</p><p>7. How many compounds of SO2 are in 7.5 moles of SO2 ? 24 = 4.5x10 compounds of SO2 (2 significant figures)</p><p>8. How many moles of NaI are in 4.8x1024 compounds of NaI ?</p><p>= 8.0 compounds of NaI (2 significant figures)</p><p>9. Calculate the molar mass of each substance below. (Round to nearest tenth place)</p><p> a. Fe (molar mass of Fe= atomic mass of Fe) = 55.8 grams</p><p> b. O2 (molar mass of O2 = atomic mass of O2 = 16g x 2 = 32 grams </p><p> c. Ca3(PO4)2 Ca3: 40.1 x 3 = 120.3g </p><p>P2: 31.0 g x 2 = 62 g</p><p>+ O8: 16 x8 = 128 g</p><p>______</p><p>310.3 grams of Ca3(PO4)2 </p><p> d.C4H9O2</p><p>C4: 12.0 x 4 = 48 g</p><p>H9: 1.0 x9 = 9.0 g</p><p>O2: 16.0x2 = +32.0 g</p><p>89.0 grams of C4H9O2</p><p>10. How many moles are in 15.5g of Al2O3?</p><p>Molar mass of Al2O3 = 102.0 g</p><p>= 0.152 moles of Al2O3</p><p>11. How many grams are in 2.5 moles of Mg3(PO4)2 ?</p><p>Molar mass of Mg3(PO4)2 = 264.4 g</p><p>= 660 grams of Mg3(PO4)2 </p><p>12. How many grams are in 3.8 moles of Fe(OH)3? Molar mass of Fe(OH)3 = 106.8 g</p><p>= 410 grams of Fe(OH)3</p><p>13. How many moles are in 0.0688 g of AgCl?</p><p>Molar mass of AgCl = 143.4 g</p><p>= 4.80x10-4 grams of AgCl</p><p>14. Which substance below contains more particles? (show your work)</p><p> a. 1 mole of CO2 b. 1 mole of Ne c. 1 mole of Na2(CO3)</p><p>They all have the same number of particles: 6.02x1023 particles</p><p>15. Rank the following substances in decreasing order based on the number of moles present in each sample. (show work)</p><p> a.50 grams of C2H6 = 1.7 moles b. 50 grams of H2O2 = 1.5 moles c. 50 grams of CO= 1.8 moles</p><p>Ranking: CO > C2H6 > H2O2</p><p>16. What is the total mass of a mixture containing the following substances:</p><p>22 a. 3.5x10 ionic compounds of Na2SO4 = 8.3 g</p><p> b. 0.500 moles of H2O = 9.00 g</p><p> c. 7.23 grams of AgCl </p><p>Total mass = 24.5 grams of mixture </p><p>17. Two step conversion problems from practice sheet. (answers are on webpage)</p><p>18. Calculate the % composition of each compound below?</p><p> a. H2S H2: 2.0g</p><p>+ S : 32.1 g</p><p>= 34.1 g H2S</p><p>%H= 5.9 %</p><p>%S= 94.1 % b. (NH4)2C2O4 : N2: 28.0g</p><p>H8: 8.0 g</p><p>C2: 24.0 g</p><p>+ O4: 64.0 g</p><p>= 124 g of (NH4)2C2O4</p><p>%N= 22.6 %</p><p>%H=6.5</p><p>%C=19.4</p><p>%O=51.6</p><p> c.Mg(OH)2 </p><p>Mg: 24.8 g</p><p>O2: 32.0 g</p><p>+ H2: 2.0 g</p><p>= 58.8 grams of Mg(OH)2</p><p>% Mg= 42.2</p><p>%O= 54.4</p><p>%H=3.4</p><p> d.Na3(PO4)</p><p>Na3: 69.0g</p><p>P: 31.0 g</p><p>+ O4: 64.0 g = 164 grams of Na3(PO4)</p><p>% Na= 42.1</p><p>%P= 18.9</p><p>% O= 39.0</p><p>19. Solve these problems using answers from question 18. </p><p> a. How many grams of sulfur is present in 3.54 g of H2S? = 3.54 x 0.941 = 3.33g of sulfur</p><p> b. How many grams of nitrogen is present in 25.0 g of (NH4)2C2O4 ?= 25.0 g x 0.226= 5.65 g of nitrogen</p><p> c. How many grams of magnesium is present in 97.4g of Mg(OH)2? = 97.4 g x 0.422 = 41.1 g of magnesium</p><p> d. How many grams of phosphorus is present in 804g of Na3(PO4)? = 804 g x 0.189 = 152 g of phosphorus</p>