chemistry

homework #7 CHE 221 General Chemistry I Concordia University—Irvine Due: 2016 September 15, 19 1. Calculate the number of moles in 52.94 g of europium, Eu. 2. Calculate the number of moles in 85.567 g of uranium(III) fluoride. 3. Calculate the mass, in grams, of 29.175 mol nickel. 4. Calculate the mass, in grams, of 6.15 mol Na3PO4. 5. A crystalline block of NaCl has dimensions of 50.3 mm × 15.4 cm × 2.47 in. How many Cl–

ions are present? d (NaCl) = 2.16

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g cm3

6. The density of oleyl alcohol (C18H36O) is d (C18H36O) = 0.850

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g cm3 . For a sample with

volume 93.2 mL, how many moles of C are present? 7. Calculate the total number of C atoms in 8.03 mol of trinitrotoluene (TNT): CH3C6H2(NO2)3. 8. Desatrine is a chemical used as an insecticide. Its chemical formula is C36H55NO12. What is

the mass percent composition of: a. carbon, C b. nitrogen, N 9. A compound used in leather tanning is composed of 44.77% C, 7.52% H, and 47.71% O by

mass. What is the empirical formula of this compound? 10. A vasodilator compound contains 59.07% C; 7.63% H; 21.20% N; and 12.11% O by

mass. What is the empirical formula of this compound?