CDO AP Chemistry Unit 1 Review 2

CDO AP Chemistry Christman Fall 2013

CDO AP Chemistry Unit 1 Review 2

1. Why is it that the vast majority of alpha particles that traveled through the gold foil in Rutherford’s experiment

experienced no deflection?

2. Describe the results of the experiment that proved electrons carry a negative charge.

3. What is an isotope?

Questions 4-7 refer to the U-238 isotope.

4. How many protons are contained within the nucleus?

5. How many neutrons are contained within the nucleus?

6. How many electrons are contained within a single neutral isotope of this element?

7. What is the mass of this isotope in amu?



8. The three naturally occurring isotopes of magnesium are: magnesium-24 (23.985 amu), magnesium-25 (24.986

amu), and magnesium-26 (25.983 amu). Their percent abundances in nature are 78.99%, 10.00%, and 11.01%

respectively. What is the average mass of magnesium?

9. There are two naturally occurring isotopes of bromine: Br-79 (78.918 amu) and Br-81 (80.916 amu). What is the

percentage of each isotope?

10. What is the empirical formula of C4H10?

11. Is CO2 an empirical formula, a molecular formula, or both? Explain.

12. Calculate the mass percent of each element in CaCO3



13. A vitamin C tablet from a certain company contains 70.0 mg of ascorbic acid (Vitamin C). The entire tablet,

however, has a mass of 0.825 g. Calculate the mass percent of Vitamin C in the tablet.

14. How many moles of acetic acid (CH3COOH) are contained within 24.71 g of acetic acid?

15. How many grams of NaOH are contained within 0.785 moles NaOH.

16. How many carbon atoms are contained in 84.3 g of ethyne (C2H2)?

17. Name the following ionic compounds:

a. Fe2O3

b. FeO

c. ZnCl2

d. AgNO3

e. PbO2

f. PbSO4



g. Mg3(PO4)2

h. NaHCO3

i. KCN

j. KMnO4

18. Write ionic formulas for the following compounds:

a. Sodium acetate

b. Tin(II) chloride

c. Calcium hydroxide

d. Ammonium sulfate

e. Manganese (II) hypochlorite

f. Copper (II) nitrite

g. Nickel(II) chlorite

h. Lead (II) nitrate

i. Potassium sulfide

j. Aluminum oxide



19. Name the following molecular compounds:

a. CO

b. CO2

c. H2O

d. CCl4

e. N2O3

f. SiO2

g. N2O4

h. CBr4

i. SO2

j. S2Cl2

20. Write molecular formulas for the following compounds:

a. Xenon hexafluoride

b. Tetranitrogen tetraoxide

c. Boron trifluoride

d. Carbon tetrabromide

e. Dicarbon tetrafluoride



f. Nitrogen tribromide

g. Dinitrogen tetrasulfide

h. Oxygen difluoride

i. Dinitrogen pentaoxide

j. Tetraphosphorus decaoxide

21. Write chemical formulas for the following compounds:

a. Carbon monoxide

b. Potassium sulfide

c. Potassium permanganate

d. Nitrogen trichloride

e. Nickel (II) sulfate

f. Sodium acetate

g. Magnesium iodate

h. Sulfur trioxide

i. Calcium carbonate

j. Silver sulfide



22. Name the following acids:

a. CH3COOH

b. HBrO3

c. H2CO3

d. H2SO4

e. HF

f. HCl

g. HI

h. H2SO3

i. HIO3

j. HCN

23. Write chemical formulas for the following acids:

a. Perchloric acid

b. Nitric acid

c. Hydroiodic acid



d. Acetic acid

e. Iodic acid

f. Nitrous acid

g. Hydrochloric acid

h. Hydrobromic acid

i. Chlorous acid

j. Bromic acid

24. Write chemical formulas for the following hydrates:

a. Magnesium perchlorate hexahydrate

b. Calcium chromate dehydrate

c. Aluminum chloride hexahydrate

d. Copper (II) sulfate pentahydrate

e. Barium chloride dehydrate



25. An experiment was performed in which a 5.00 g sample of aluminum metal was burned in oxygen to produce

9.45 g of aluminum oxide. Use this data to determine the empirical formula of the aluminum oxide.

26. When crystalline copper (II) sulfate, CuSO4 xH2O is heated in air above 100˚ C, it loses the water molecules and

also its blue color. If 9.60 g of CuSO4 is left after heating 15.01 g of the hydrate, calculate the number of moles of

water originally present in the compound and then determine the value of “x” in the formula.



27. It was found that a compound contained 68.1% carbon 13.7% hydrogen and 18.2% oxygen by mass. Determine

the empirical and molecular formula of the compound if the molar mass is 176.34 g/mol.

Balancing Equations Balance the Following Equations

28. Ca + HOH Ca(OH)2 + H2

29. Cl2O7 + H2O HClO4

30. Fe + O2 Fe3O4

31. C6H14 + O2 CO2 + H2O

32. Ca3(PO4)2 + H2SO4 Ca(H2PO4)2 + CaSO4



Stoichiometry

33. Answer the following questions for this equation: 2H2 + O2 2H2O

a. What is the H2/H2O ratio?

b. Suppose you had 20 moles of H2 on hand and plenty of O2, how many moles of H2O could you make?

c. What is the O2/H2O mole ratio?

d. Suppose you had 20 moles of O2 and enough H2, how many moles of H2O could you make?

34. Given the following equation: 2K + Cl2 KCl How many grams of KCl are produced from 2.50 g of K and

excess Cl2.



35. Given the following equation: 2NaClO3 2NaCl + 3O2 How many grams of NaCl are produced when 80.0

grams of O2 are produced?

36. The reusable booster rockets of the U.S. space shuttle employ a mixture of aluminum and ammonium perchlorate

for fuel. A possible equation for this reaction is: 3Al(s) + 3NH4ClO4(s) Al2O3(s) + AlCl3(s) + 3NO(g) +

6H2O(l) What mass of NH4ClO4 should be used in the fuel mixture for every kilogram of aluminum?

37. In the reaction PCl5 --> PCl3 + Cl2, 104.3 g of PCl5 are used, and 30.0 g of Cl2 are produced. What is the % yield

of Cl2 in this reaction?



38. Methane (CH4) reacts with O2 to form CO2 and water. If 30.0 grams of CH4 and 64.0 grams of O2 are mixed and

the reaction goes to completion, how many grams of H2O will form?

39. How many grams of CO2 can be produced from 7.61 grams CS2 and 8.00 grams O2 in the following reaction:

CS2 + 3O2 --> CO2 + 2SO2



40. A 84.1 g sample of phosphorous reacts with 85.0 g oxygen gas to form diphosphorus pentoxide.

a. What is the limiting reactant?

b. What is the theoretical yield in grams of P2O5?

c. If only 123 g of P2O5 are produced, what is the percentage yield?

41. In the combustion of CH4 (methane) to give CO2 and water, when 10.0 grams of CH4 are mixed with 10.0 grams

of O2, how many grams remain (if any) of the reagent "in excess"?



42. A 1.0857 g sample of a compound containing only carbon, hydrogen and oxygen was burned in excess oxygen.

3.190 g of carbon dioxide and 0.9360 g of water were produced. Find the empirical formula of the compound.

43. A confiscated white substance, suspected of being cocaine, was purified by a forensic chemist and subjected to

elemental analysis. Combustion of a 50.86-mg sample yielded 150.0 mg CO2 and 46.05 mg H2O. Analysis for

nitrogen showed that the compound contained 9.39% N by mass. The formula of cocaine is C17H21NO4. Can the

forensic chemist conclude that the suspected compound is cocaine?

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CDO AP Chemistry Unit 1 Review 2