Accelerated Chemistry Chapter 7,8,9 review Name KEY!!!
Perform all work on one piece of loose-leaf paper and hand in at the end of the period.
1. Perform the following conversions:
a. 78.2 g of Potassium to moles and atoms 2.00 moles, 1.20 x 1024 atoms
b. 3.00 moles of Carbon dioxide to liters, molecules, and grams 67.2 L, 1.81 x 1024 molecules, 132 g
c. 1.20 x 1024 molecules of Fluorine to grams, moles, and liters 75.7 g, 1.99 moles, 44.7 L
d. 6.02 x 1023 atoms of oxygen to molecules of oxygen 3.01 x 1023 molecules
e. 6.02 x 1023 atoms of oxygen to molecules of ozone (look up its formula)
2.01 x 1023 molecules
2. Why can’t you convert g of Potassium to liters? Why can you convert moles of carbon dioxide and molecules of Fluorine to liters? Potassium is not a gas – it’s a solid – 22.4 L/mole is a conversion for gases only. You can convert CO2 and F2 to liters because they are gases.
3. Calculate the % composition of each atom in CSCl2. C = 10.4%, S = 27.9%,
Cl = 61.7%
4. If a compound is decomposed and yields 2.40 g of carbon, 3.20 g of oxygen, and 0.400 g of hydrogen, what is the empirical formula. What is the molecular formula if the molar mass is 60.0 g/mole? % composition = 40.0 % C, 53.3 % O, H = 6.7% so empirical formula = CH2O, molecular formula = C2H4O2
5. Write balanced formula equations that represent the following reactions. Include heat and symbols (phases) in your equations.
a. The combustion of pentane (C5H12) – exothermic
C5H12(g) + 8 O2(g) → 5 CO2(g) + 6 H2O(g) + heat
b. The reaction of aluminum chloride with silver nitrate (neglect heat)
AlCl3(aq)) + 3 AgNO3(aq) → 3 AgCl(s) + Al(NO3)3(aq)
c. The reaction of H2SO4 with Iron (III) hydroxide (exothermic)
3 H2SO4(aq) + 2 Fe(OH)3 (aq) → Fe2(SO4)3 (aq) + 6 H2O(l) + heat
d. The reaction of sodium hydroxide with HCl (exothermic)
NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (l) + heat
e. The synthesis of Aluminum oxide (endothermic)
4 Al (s) + 3 O2(g) + heat → 2 Al2O3 (s)