PRACTICE PROBLEMS FOR EXAM ONE
CHEM 1311
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CHAPTER 1; 2; 3
CHAPTER ONE
1. The density of titanium is 4.54 g/mL. What is the mass of 0.0173 L of Ti?
2. Convert the area of a rectangle 0.730 in2 into mm2 ?
3. The specific heat of Al is 0.900 J/g °C. How many joules of heat are absorbed by 0.015 kg of Al if it is heated
from 20°C to 60.0°C?
4. The label on a container of olive oil says 1.75 gal. How many milliliters is this?
CHAPTER TWO
5. How many phosphorus atoms are in 4.32 x 103 molecules of Ca3(PO4)2 ?
6. How many moles is 41.3 g of CH4?
7. What is the mass of S in 25.4 g of Cr2(SO4)3 ?
8. What is the percent composition of lead in 5.05 kg of mendipite, PbCl22PbO?
9. The density of toluene (C7H8) is 0.866 g/mL. What’s the number of moles of C atoms in 2.4 L of toluene?
10. How many moles of hydrogen atoms are in 56.7 moles of (NH4)3PO4 ?
11. How many sulfur atoms are in 2.65 grams of Cr2(SO4)3 ?
12. A compound containing only nitrogen and oxygen is found to be 36.8% nitrogen and 63.2% oxygen. Its
formula weight is 76.0 g/mol. What is the molecular formula for this compound?
CHAPTER THREE
13. How many moles of NH3 are needed when 12.2 g of H2O was produced?
4 NH3 + 5 O2 —> 4 NO + 6 H2O
14. What is the molarity of 175 ml of solution containing 2.18 g of Na2SO410H2O?
15. How many milliliters of 0.385 M HNO3 is required to react with 48.0 mL of 0.077M Ca(OH)2 ?
2 HNO3 + Ca(OH)2 —> CaCl2 + 2 H2O
16. What is the percent yield of elemental sulfur if 7.54 g of sulfur are obtained from the reaction of 6.16 g of
SO2 with an excess of H2S? 2 H2S + SO2 —> 2 H2O + 3 S
17. How many grams of N2 are necessary to produce 7.5 g of NH3? ? N2 + ?H2 —> ? NH3
18. What mass of CaCl2 must be dissolved in enough water to produce 2125 mL of 1.25 M CaCl2 ?
19. How many grams of nitric acid can be prepared from the reaction of 62.5 g of nitrogen dioxide with 36.0 g
of water?
3 NO2 + H2O —> 2 HNO3 + NO
20. What is the molarity of 345 ml of HCl if 5.6 grams of ZnCl2 are produced from HCl reaction with excess Zn
metal?
? Zn + ? HCl —> ? ZnCl2 + ? H2
ANSWERS:
1) 78.5 g
2) 471.0 mm2
3) 540 J
4) 6604 mL
5) 8.64 x 103 atoms
6) 2.58 mol
7) 6.24 g
8) 85.8 %
9) 158.1 mol
10) 680.4 mol
11) 1.22 x 1022 atoms
12) N2O3
13)0.45 mol
14) 0.039 M
15) 19.2 mL
16) 81.5 %
17) 6.18 g
18) 295.1 g
19) 57.1 g
20) 0.24 M