Advanced Chemistry Bell Ringers Quarter 2 Bell Ringer

Advanced Chemistry Bell Ringers Quarter 2

Bell Ringer 11 -2 -15 How many valence electrons are in each of these atoms or ions? Xe, Sr 2+, Cl, and Cl–

Exit Closing 11 -2 -15 Draw Lewis structures for the following molecular compounds and ions: (a) Al. Cl 3, (b) PH 3; (c) H 2 Se; (d) NO 2–; (e) Al. H 4–.

Bell Ringer 11 -3 -15 How do the electronegativities of the elements change across a row and down a group in the periodic table?

Exit Closing 11 -3 -15 Which is the least polar bond? C—Se C==O Cl—Br O==O N—H C—H

Bell Ringer 11 -4 -15 What factors determine whether or not a molecule or ion exhibits resonance?

Exit Closing 11 -4 -15 Oxygen and sulfur combine to form a variety of different sulfur oxides. Some are stable molecules and some, including S 2 O 2 and S 2 O 3, decompose when they are heated. Draw Lewis structures for the two compounds showing all resonance forms.

Bell Ringer 11 -5 -15 How do the electronegativities of elements influence the selection of which Lewis structure is favored?

Exit Closing 11 -5 -15 Origins of Life The discovery of polyatomic organic molecules such as cyanamide (H 2 NCN) in interstellar space has led some scientists to believe that the molecules from which life began on Earth may have come from space. Draw Lewis structures for cyanamide, and select the preferred structure on the basis of formal charges.

Bell Ringer 11 -6 -15 In which of the following molecules does the phosphorus atom have an expanded valence shell? (a) POCl 3; (b) PF 5; (c) PF 3; (d) P 2 F 4 (which has a P P bond)

Exit Closing 11 -6 -15 Which of the following nitrogen oxides are odd-electron molecules? (a) NO; (b) NO 2; (c) NO 3; (d) N 2 O 4; (e) N 2 O 5

Bell Ringer 11 -9 -15 Rank the following ions in order of increasing carbon–oxygen bond lengths: CO, CO 2, and CO 32–.

Exit Closing 11 -9 -15 Rank the following ions in order of increasing carbon–oxygen bond energy: CO, CO 2, and CO 32–.

Bell Ringer 11/10/15 Chapters 3 & 4 Exam Pick up your remote from the CPS bag. Be sure that it is YOUR number. Begin testing immediately. You may use: Scratch paper and a NON-Programmable Calculator. No Cell Phones!

Exit Closing 11/10/15 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 11/11/15 Day 1 of 4 Foundry Lab (In the Library Days 1 & 4) Your lab notebook should focus on Short Intro with prediction, procedures, Safety, and Data Formal Write Up Should Include: Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

Exit Closing 11/11/15 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 11/12/15 Day 2 of 4 Foundry Lab Data Collection Day! Your lab notebook should focus on Short Intro with prediction, procedures, Safety, and Data Formal Write Up Should Include: Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

Exit Closing 11/12/15 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 11/13/15 Day 3 of 4 Foundry Lab Data Collection Day! Your lab notebook should focus on Short Intro with prediction, procedures, Safety, and Data Formal Write Up Should Include: Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

Exit Closing 11/13/15 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 11/16/15 Day 4 of 4 Foundry Lab (In the Library Days 1 & 4) Your lab notebook should focus on Short Intro with prediction, procedures, Safety, and Data Formal Write Up Should Include: Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

Exit Closing 11/16/15 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 11/17/15 In which molecular geometry do equatorial bonding pairs of electrons repel each other more: square pyramidal or trigonal bipyramidal?

Exit Closing 11/17/15 The O–N–O bond angle in NO 2 is slightly larger than it is in NO 2–. Why?

Bell Ringer 11/18/15 Rank the following molecules in order of increasing bond angles: (a) NH 3; (b) CH 4; (c) H 2 O.

Exit Closing 11/18/15 Determine the molecular geometries of the following molecules and ions: (a) NO 3– (b) NO 43– (c) NCN 2– (d) NF 3.

Bell Ringer 11/19/15 Determine the molecular geometries of the following ions: (a) SCN–; (b) CH 3 PCl 3+ (P is the central atom and is bonded to the C atom of the methyl group); (c) ICl 2–; (d) PO 33–.

Exit Closing 11/19/15 Which two of the species N 3–, O 3, and CO 2 have the same molecular geometry?

Bell Ringer 11/20/15 Must a polar molecule contain polar covalent bonds? Why?

Exit Closing 11/20/15 Which of the following molecules has a permanent dipole? (a) C 4 F 8 (cyclic structure); (b) Cl. FCCF 2; (c) Cl 2 HCCCl. F 2

Bell Ringer 11/23/15 Which molecule in each of the following pairs is more polar? (a) NH 3 or PH 3; (b) CCl 2 F 2 or CBr 2 F 2

Exit Closing 11/23/15 What is the hybridization of nitrogen in each of the following ions and molecules? (a) NO 2+; (b) NO 2–; (c) N 2 O; (d) N 2 O 5; (e) N 2 O 3

Bell Ringer 11/24/15 How does the hybridization of the sulfur atom change in the series SF 2, SF 4, SF 6?

Exit Closing 11/24/15 What is the molecular geometry around sulfur and nitrogen in the sulfamate anion shown in Figure P 5. 73? Which atomic or hybrid orbitals overlap to form the S–O and S–N bonds in the sulfamate anion?

Bell Ringer 11/30/15 Which of the molecules in Figure P 5. 82 are chiral?

Exit Closing 11/30/15 Which of the molecules in Figure P 5. 84 are chiral?

Bell Ringer 12/1/15 Do all σ molecular orbitals result from the overlap of s atomic orbitals?

Exit Closing 12/1/15 Do all π molecular orbitals result from the overlap of p atomic orbitals?

Bell Ringer 12/2/15 Diatomic noble gas molecules, such as He 2 and Ne 2, do not exist. Would removing an electron create molecular ions, such as He 2+ and Ne 2+, that are more stable than He 2 and Ne 2?

Exit Closing 12/2/15 Which of the following molecular ions are diamagnetic? (a) O 2–; (b) O 22– ; (c) N 22–; (d) F 2+

Bell Ringer 12/3/15 Which of the following molecular cations have electrons in π antibonding orbitals? (a) N 2+; (b) O 2+; (c) C 22+; (d) Br 22+

Exit Closing 12/3/15 For which of the following diatomic molecules does the bond order increase with the loss of two electrons, forming the corresponding 2+ cation? (a) B 2; (b) C 2; (c) N 2; (d) O 2

Bell Ringer 12/4/15 Cl 2 O 2 may play a role in ozone depletion in the stratosphere. Draw the Lewis structure for Cl 2 O 2 based on the skeletal structure in Figure P 5. 110. What is the geometry about the central chlorine atom?

Exit Closing 12/4/15 Ozone Depletion In 1999, the Cl. O+ ion, a potential contributor to stratospheric ozone depletion, was isolated in the laboratory. a. Draw the Lewis structure for Cl. O+. b. Using the molecular orbital diagram for Cl. O+ in Figure P 5. 113, determine the order of the Cl–O bond in Cl. O+.

Bell Ringer 12/7/15 Early Earth Some scientists believe that an anion with the skeletal structure shown in Figure P 5. 114 may have played a role in the formation of nucleic acids before life existed on Earth. a. Complete the Lewis structure of this anion. b. Predict the C—P—O bond angle in the anion.

Exit Closing 12/7/15 Two compounds formed by the reaction of boron with carbon monoxide have these skeletal structures: B–B–C–O and O–C–B–B–C–O. a. Draw the Lewis structures of both compounds that minimize formal charges. b. What are the B–B–C bond angles in the molecules?

Bell Ringer 12/8/15 The three most abundant gases in air are N 2, O 2, and Ar. Which of them has the highest boiling point, and which has the lowest boiling point?

Exit Closing 12/8/15 How are water molecules oriented around cations in aqueous solutions?

Bell Ringer 12/9/15 Why is the boiling point of Br 2 lower than that of iodine monochloride, ICl, even though they have nearly the same molar mass?

Exit Closing 12/9/15 Molecules of which of these compounds: CO 2, NO 2, SO 2, or H 2 S, experience dipole–dipole interactions?

Bell Ringer 12/10/15 In an aqueous solution containing Na+, Mg 2+, K+, and Ca 2+ salts, which cation would you expect to experience the strongest ion–dipole interactions?

Exit Closing 12/10/15 In each of the following pairs of compounds, which compound is likely to be more soluble in CCl 4? a. Br 2 or Na. Br b. CH 3 CH 2 OH or CH 3 OCH 3 c. CS 2 or KOH d. I 2 or Ca. F 2

Bell Ringer 12/11/15 Rank the ketones in Figure P 6. 40 from least soluble to most soluble in water.

Exit Closing 12/11/15 Below what temperature can solid CO 2 (dry ice) be converted into CO 2 gas simply by lowering the pressure?

Bell Ringer 12/14/15 A hot needle sinks when placed on the surface of cold water, but a cold needle floats. Why?

Exit Closing 12/14/15 The mercury level in a capillary tube inserted into a dish of mercury is below the surface of the mercury in the dish. Why?

Bell Ringer 12/15/15 Chapters 5 & 6 Exam Pick up your remote from the CPS bag. Be sure that it is YOUR number. Begin testing immediately. You may use: Scratch paper, Periodic Table and a NON-Programmable Calculator. No Cell Phones!

Bell Ringer 12 -16 -15 Write a balanced chemical equation for each of the following reactions: a. Carbon dioxide reacts with carbon to form carbon monoxide. b. Potassium reacts with water to give potassium hydroxide and the element hydrogen. c. Phosphorus (P 4) burns in air to give diphosphorus pentoxide.

Exit Closing 12 -16 -15 Charcoal (C) and propane (C 3 H 8) are used as fuel in backyard grills. a. Write balanced chemical equations for the complete combustion reactions of C and C 3 H 8. b. How many grams of carbon dioxide are produced from burning 500. 0 grams of each of the two fuels?

Bell Ringer 12 -17 -15 Lead Compounds as Pigments Ancient Egyptians used lead compounds including Pb. S, Pb. CO 3, and Pb 2 Cl 2 CO 3 as pigments in cosmetics, and many people suffered from chronic lead poisoning as a result. Calculate the percentage of lead in each of the compounds.

Exit Closing 12 -17 -15 A sample of an iron-containing compound is 22. 0% iron, 50. 2% oxygen, and 27. 8% chlorine by mass. What is the empirical formula of this compound?

Bell Ringer 12 -18 -15 Ferrophosphorus (Fe 2 P) reacts with pyrite (Fe. S 2), producing iron(II) sulfide and a compound that is 27. 87% P and 72. 13% S by mass and has a molar mass of 444. 56 g/mol. a. Determine the empirical and molecular formulas of the compound. b. Write a balanced chemical equation for the reaction.

Exit Closing 12 -18 -15 A reaction vessel contains 10. 0 g CO and 10. 0 g O 2 which combine to form CO 2: 2 CO(g) + O 2(g) → 2 CO 2(g) a. Which reactant is the limiting reactant? b. How many grams of CO 2 could be produced? c. How many grams of the nonlimiting reactant are left over?

Bell Ringer 1 -4 -16 Calculate the molarity of each of the following solutions: a. 0. 150 mol urea [(NH 2)2 CO] in 250. 0 m. L of solution b. 1. 46 mol NH 4 CH 3 CO 2 in 1. 000 L of solution c. 1. 94 mol methanol (CH 3 OH) in 5. 000 L of solution d. 0. 045 mol sucrose (C 12 H 22 O 11) in 50. 0 m. L of solution

Exit Closing 1 -4 -16 Chemists who analyze samples for dissolved trace elements may buy standard solutions that contain 1. 000 g/L concentrations of the elements. If a chemist wishes to prepare 0. 500 L of a working standard that has a concentration of 5. 00 mg/L, what volume of the 1. 000 g/L standard is needed?

Bell Ringer 1 -5 -16 What is the molarity of each ion in a 0. 025 M aqueous solution of (a) KCl; (b) Cu. SO 4; (c) Ca. Cl 2?

Exit Closing 1 -5 -16 Write a balanced molecular equation and a net ionic equation for the following reactions: a. Solid aluminum hydroxide reacts with a solution of hydrobromic acid. b. A solution of sulfuric acid reacts with solid sodium carbonate. c. A solution of calcium hydroxide reacts with a solution of nitric acid.

Bell Ringer 1 -6 -16 Given the following equation, how many grams of Pb. CO 3 will dissolve when 1. 00 L of 1. 00 M H+ is added to 5. 00 g of Pb. CO 3? Pb. CO 3(s) + 2 H+(aq) → Pb 2+(aq) + H 2 O(ℓ) + CO 2(g)

Exit Closing 1 -6 -16 How many milliliters of 0. 100 M HNO 3 are needed to neutralize the following solutions? a. 45. 0 m. L of 0. 667 M KOH b. 58. 5 m. L of 0. 0100 M Al(OH)3 c. 34. 7 m. L of 0. 775 M Na. OH

Bell Ringer 1 -7 -16 An expanding gas does 150. 0 J of work on its surroundings at a constant pressure of 1. 01 atm. If the gas initially occupied 68 m. L, what is the final volume of the gas?

Exit Closing 1 -7 -16 Calculate ∆E for a system that absorbs 726 k. J of heat from its surroundings and does 526 k. J of work on its surroundings.

Bell Ringer 1 -8 -16 The same quantity of thermal energy is added to equal masses of four metals: titanium, iron, silver, and lead. All of them are initially at the same temperature. Which metal has the highest final temperature?

Exit Closing 1 -8 -16 A 20. 0 g piece of iron and a 20. 0 g piece of gold at 100. 0°C are dropped into 1. 00 L of water at 20. 0°C. What is the final temperature of the water and pieces of metal?

Bell Ringer 1 -11 -16 Calculate the heat capacity of a calorimeter if the combustion of 4. 663 g of benzoic acid produces an increase in temperature of 7. 149°C.

Exit Closing 1 -11 -16 Ozone Layer The destruction of the ozone layer by chlorofluorocarbons (CFCs) can be described by the following reactions: Cl. O(g) + O 3(g) → Cl(g) + 2 O 2(g)  ∆H°rxn = – 29. 90 k. J 2 O 3(g) → 3 O 2(g) ∆H°rxn = +24. 18 k. J Use the above ∆H°rxn values to determine the value of the standard heat of reaction for this reaction: Cl(g) + O 3(g) → Cl. O(g) + O 2(g)  ∆H°rxn = ?

Bell Ringer 1 -12 -16 No Time To Spare!!! ACS Review Day Atomic Structure

Bell Ringer 1 -13 -16 No Time To Spare!!! ACS Review Day Molecular Structure & Bonding

Bell Ringer 1 -14 -16 No Time To Spare!!! ACS Review Day Stoichiometry

Bell Ringer 1 -15 -16 No Time To Spare!!! ACS Review Day States of Matter

Bell Ringer 1 -19 -16 No Time To Spare!!! ACS Review Day Energetics

Bell Ringer 11/21/16 Advanced Chemistry Final Exam Pick up your remote from the CPS bag. Be sure that it is YOUR number. Begin testing immediately. You may use: Scratch paper, Periodic Table and a NON-Programmable Calculator. No Cell Phones!

Bell Ringer 1 -22 -16 At an elevation where the boiling point of water is 93°C, 1. 33 kg of water at 30°C absorbs 290. 0 k. J from a mountain climber’s stove. Is this amount of thermal energy sufficient to heat the water to its boiling point?

Bell Ringer 1 -25 -16 Use the information in the following two thermochemical equations: NO 2 Cl(g) → NO 2(g) + 1/2 Cl 2(g) ∆H°rxn = – 114 k. J 1/2 N 2(g) + O 2(g) → NO 2(g) ∆H°rxn = +33. 2 k. J to calculate the value of ∆H°rxn for this reaction: 1/2 N 2(g) + O 2(g) + 1/2 Cl 2(g) → NO 2 Cl(g)  ∆H°rxn = ?

Exit Closing 1 -25 -16 For which of the following reactions does ∆H°rxn also represent a heat of formation? a. 2 N 2(g) + 3 O 2(g) → 2 NO 2(g) + 2 NO(g) b. N 2(g) + O 2(g) → 2 NO(g) c. 2 NO 2(g) → N 2 O 4(g) d. N 2(g) + 2 O 2(g) → 2 NO 2(g)

Bell Ringer 1 -26 -16 Take out your take home essay quizzes… Which question is your most difficult and which is the easiest? Which question is the most difficult to write about and which is the easiest?

Exit Closing 1/26/16 We will entertain 3 questions or comments before we leave today. You have one minute to write down one question that you should be prepared to share.

Bell Ringer 1/27/16 Chapters 7, 8, & 9 Exam Pick up your remote from the CPS bag. Be sure that it is YOUR number. Begin testing immediately. You may use: Scratch paper, Periodic Table and a NON-Programmable Calculator. No Cell Phones!