AP Chemistry Prep - Summer Assignment 2013 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which value has only 4 significant digits? a. 6.930 c. 8450 b. 0.0450 d. 0.392 2. Which is the sum of these values, to the appropriate number of significant digits? 17.358 + 3.502 + 20.14 = a. 41 c. 41.000 b. 41.00 d. 41.0 3. Which is the product of these numbers, to the appropriate number of significant digits? 56.2 9.2057 = a. 517 c. 517.36 b. 517.4 d. 517.00 4. How many significant digits are in the value 530,405,000? a. 4 c. 6 b. 5 d. 9 5. How many significant digits are in the value 0.0050340? a. 3 c. 7 b. 5 d. 8 Atoms Atom Protons Neutrons Electrons Mass Number Sodium 12 23 Chlorine 17 17 35 6. According to the table above, how many neutrons are in an atom of chlorine? a. 17 c. 34 b. 18 d. 35 7. According to the table above, how many electrons are in an neutral atom of sodium? a. 22 c. 12 b. 11 d. 23 8. Which is the number of protons in? a. 26 c. 56 b. 30 d. 82 9. Which is the number of neutrons in? a. 35 c. 80 b. 45 d. 115
10. Which is the correct formula for the compound formed between beryllium and nitrogen? a. BeN c. Be 3 N 2 b. Be 3 N d. Be 2 N 3 11. What is the correct formula for the compound formed between magnesium and the phosphate ion? a. MgPO 4 c. Mg 3 (PO 4 ) 2 b. Mg 3 PO 2 d. MgP 2 O 8 12. Which is the correct formula for the compound Manganese (III) Fluoride? a. MnF c. MnF 3 b. Mn 3 F d. Mn 3 F 3 13. Which is the correct formula for the compound Chromium (II) Nitrate? a. (Cr) 2 NO 3 c. CrNO 2 b. Cr 2 NO 3 d. Cr(NO 3 ) 2 14. Which is the correct name for the compound FeS? a. Iron Sulfide c. Iron (II) Sulfide b. Iron (I) Sulfide d. Iron (II) Sulfide (II) 15. Which is the correct name for the compound Na 3 P? a. Sodium Phosphide c. Sodium Phosphate b. Sodium Phosphite d. Sodium (III) Phosphide 16. Which is the correct name for the compound CoCO 3? a. Carbon Oxygen Carbonate c. Cobalt Carbonate b. Cobalt (II) Carbonate d. Cobalt Carbonoxide 17. Which is the correct name for the compound CaClO 2? a. calcium chloride c. calcium chlorite b. calcium perchlorate d. calcium chlorate 18. Which is the correct name for the compound NH 4 SO 4? a. Nitrogen Hydrogen Sulfate c. Ammonium (II) Sulfate b. Nitrogen Hydrosulfate d. Ammonium Sulfate 19. Which of the following acids is named incorrectly? a. HC 2 H 3 O 2 ; acetic acid c. H 2 SO 3 ; sulfurous acid b. HBr ; bromic acid d. HClO 3 ; chloric acid 20. Which of the following elements is a metal? a. Boron c. Magnesium b. Nitrogen d. Carbon 21. Which type of reaction can be recognized by the general pattern? a. combustion c. single replacement b. synthesis d. decomposition 22. Which type of reaction takes place in the presence of oxygen and produces carbon dioxide and water? a. decomposition c. synthesis b. double replacement d. combustion
23. Which type of reaction is SiO 2 + HF SiF 4 + H 2 O? a. synthesis c. single replacement b. double replacement d. combustion 24. What are the correct coefficients when this equation is balanced? Sb + O 2 Sb 4 O 6 a. 1, 2, 10 c. 4, 3, 1 b. 4, 6, 1 d. 10, 5, 1 25. Which are the product(s) of this reaction? Mg + N 2 a. NMg c. Mg 2 N 3 b. MgN d. Mg 3 N 2 26. What are the correct coefficients when this chemical equation is balanced? P 4 + O 2 P 2 O 5 a. 4, 2, 7 c. 2, 5, 4 b. 1, 1, 1 d. 1, 5, 2 27. Which is the molar mass of the element Calcium? a. 20 g/mol c. 40.078 g/mol b. 40 g/mol d. 20.180 g/mol 28. Which is the correct molar mass for the compound FeSO 4? a. 103.85 g/mol c. 415.4 g/mol b. 151.85 g/mol d. 247.85 g/mol 29. Which is the mass of 8 moles of sodium chloride? a. 7.3 grams c. 0.137 g/mole b. 468 grams d. 468 moles 30. How many grams are in 1.946 moles of NaCl? a. 113.8 g c. 0.033 g b. 30.1 g d. 44.7 g 31. Calculate the number of molecules in 4.0 mol H 2 O. a. 0.60 10 23 molecules c. 2.4 10 23 molecules b. 2.4 10 24 molecules d. 2.4 10 23 molecules 32. Which is the correct mole ratio for aluminum chloride to chlorine in the chemical reaction AlCl 3 + Br 2 AlBr 3 + Cl 2? (Is the equation balanced?) a. 1:1 c. 1:3 b. 2:3 d. 3:2 33. Determine the empirical formula of a compound that contains 40.0% carbon, 53.3% oxygen and 6.67% hydrogen by mass. a. CH 2 O c. C 2 H 2 O b. C 3 H 7 O 3 d. CHO 2 34. What is the percent composition of silicon nitride (Si 3 N 4 )? a. 30.21% Si and 68.79% N c. 54.03% Si and 45.97% N b. 42.92% Si and 57.08% N d. 60.06% Si and 39.94% N
35. The empirical formula for a compound is CH 2 O, and the molar mass is 180.2g/mol. Which is the molecular formula for this compound? a. C 6 H 12 O 6 c. C 8 H 20 O 4 b. C 7 H 16 O 5 d. C 3 H 6 O 3 36. How many moles of KBr will be produced from 7 moles of BaBr 2? BaBr 2 + K 2 SO 4 KBr + BaSO 4 ( Is the equation balanced?) a. 1 mole c. 14 moles b. 7 moles d. 3.5 moles 37. How many moles of Al would be produced from 20 moles of Al 2 O 3? Al 2 O 3 Al + O 2 (Is the equation balanced?) a. 10 moles c. 40 moles b. 20 moles d. 4 moles 38. If 16.4 g of oxygen gas react with excess hydrogen gas, what mass of water can be produced? (write and balance the equation first) a. 9.23g c. 20.4g b. 18.5g d. 23.9g 39. Solid sodium metal and liquid water react to form sodium hydroxide and hydrogen gas. What mass of Na will be needed to react with excess water to produce 15.0g NaOH? (write and balance the equation first) a. 4.3g c. 8.6g b. 5.4g d. 11g 40. What is the number of moles of carbon dioxide produced from the complete combustion of 5.42 moles of ethanol (C 2 H 6 O). Write and balance the equation first. Remember, the combustion of ethanol requires oxygen gas and produces carbon dioxide gas and water. a. 5.42 moles c. 10.84 moles b. 2.71 moles d. 16.3 moles Short Answer 41. Write the formulas for each of the following compounds: a) silicon dioxide b) sodium sulfite c) nitrogen trichloride d) hydrobromic acid e) calcium iodide f) sulfurous acid
g) cesium perchlorate h) ammonia i) tin (II) fluoride j) sulfur hexafluoride k) potassium chlorate l) aluminum nitride m) sodium peroxide n) nitric acid o) ammonium sulfite p) diphosphorous pentoxide q) cobalt (III) nitrate 42. How many oxygen atoms are there in 2.54 mg of Ca(OH) 2? SHOW ALL WORK AND SIG FIGS FOR CALCULATIONS!! _ 43. A sample of methane (CH 4 ) has a mass of 31.1 g. How many molecules of methane are in this sample? SHOW ALL WORK AND SIG FIGS FOR CALCULATIONS!! _
44. Which compound has the highest percent by mass of oxygen? Ba(OH) 2, Cu(NO 3 ) 2, H 2 O, H 2 SO 4, H 2 O 2 (show work) 45. Use the following reaction to answer questions a-g Solid aluminum metal reacts with oxygen gas to produce solid aluminum oxide. SHOW ALL WORK AND SIG FIGS FOR CALCULATIONS!! a. Write and balance the equation above, including symbols for the states of matter. b. How many moles of oxygen gas will it take to react completely with 0.400 moles of aluminum? c. How many grams of oxygen gas is this? d.how many grams of aluminum are in 0.400 moles? e. How many grams of aluminum oxide can be produced from 0.400 moles of aluminum? f. Add the masses of reactants used: g. Add the masses of products formed: h. How does the mass from part f compare to the mass from part g? What chemical law does this illustrate? _
46. If 11.9g of magnesium chloride reacts with 34.2g of silver nitrate: a) Write and balance the chemical reaction that occurs b) Write the net ionic reaction that occurs. (You musts determine which of the products is not soluble and will precipitate.) c) Determine the limiting reactant d) How many grams of the precipitate can theoretically be produced? e) What is the mass of excess reactant?