Advanced Chemistry

Bell Ringers Semester 1

Bell Ringer 8/26/15

Welcome Back!

Please take a moment to write down some materials you will need for this class:

2 composition book lined, 1 composition book graphing, calculator with scientific notation and ability to do log functions, pens for labs, pencils for homework, and $20 lab fee.

The melting point of pure benzoic acid is 122°C. Data obtained by four students in a laboratory experiment are

shown. Which student’s data are precise but not accurate?

Student A Student B Student C Student D 115°C 119°C 122°C 118°C

112°C 118°C 121°C 120°C

118°C 119°C 122°C 124°C

116°C 120°C 121°C 126°C

A) Student A B) Student B

C) Student C D) Student D

Exit Closing 8/26/15

Which of these are chemical properties of matter?

I) CorrosivenessII) DensityIII) FlammabilityIV) Melting point

A) I and II B) I and III

C) II and IV D) III and IV

Bell Ringer 8/27/153 Question Mini Pre-Quiz

Which of these atomic and/or molecular views represent pure substances?

A) I and III B) II and IV

C) I, II and IV D) II, III, and IV

I I I I I I I V

Extensive properties of a pure substance depend on sample size whereas intensive properties are characteristic of that substance. Which of these properties are intensive?

I) Color II) Mass III) Density

A) I and II B) I and III C) II and III D) I, II and III

Exit Closing 8/27/15

What are the bubbles in the bottom of a boiling pot of water?

Bell Ringer 8/28/15

What do the bubbles in the bottom of a boiling pot of water have to do with the ideal gas law?

P1V1 = P2V2

T1 T2

Exit Closing 8/28/15

Turn to page 8 of your book and copy your own version of the flow chart into your

composition book.

Bell Ringer 8/31/15

Use the graduated cylinder and pipette to

prove that you can put 8.5 ml of water in your

cylinder. When you think your meniscus is in the

correct position, call me over to initial a sketch of

the cylinder that you have recorded in your book.

Exit Closing 8/31/15

Write one sentence that explains what zeros and significant and which are not. Be

prepared to share.

In which of these measured values are the zeros not significant figures?

I) 0.0591 cm II) 504 gIII) 2.70 m IV) 5300 L

A) I and II B) II and III C) I and IV

D) I, III, and IV  E) II, III, and IV

Bell Ringer 9/1/15

Exit Closing 9/1/15

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 9/2/15Use the triple beam balance to measure your

object. Sketch the slider bars into your notebook and record its mass. When you think you are

accurate call me over for a signature.

Exit Closing 9/2/15

What do graduated cylinder and triple beam measurements have to do with

significant digits?

Bell Ringer 9/3/15

The answer to the problem below is: 101Explain how you reach this answers and the steps you would take to solve it.

67.304 + 5.0 x 6.14 + 3.1 =

Exist Closing 9/3/15

Write one sentence to explain the rounding rule for if the digit you are cutting off is a 5.

Example: Round 37.85 to three sig figs

Or

Example: Round 37.95 to three sig figs

Bell Ringer 9/4/15Determining the density of an egg is difficult. Propose how you would use water, salt, an egg and a container to calculate the density of an egg. Remember that D = Mass/Volume. Hint…Hint…

A metal sample is hammered into a rectangular sheet with an area of 31.2 ft2 and an average thickness of 2.30 × 10−6 cm. If the mass of this sample is 0.4767 g, predict the identity of the metal.

The density of the metal is shown in parenthesis. Useful information: 1 in = 2.54 cm

A) Aluminum (2.70 g/cm3) B) Copper (8.95 g/cm3)

C) Gold (19.3 g/cm3) D) Zinc (7.15 g/cm3)

Exit Closing 9/4/15

Bell Ringer 9/8/15

Referring to 1.7 Write a brief explanation of the COAST

framework for solving problems.

Exit Closing 9/8/15

Convert 100 ml to liters using the COAST framework. Note that this is a simple problem to

illustrate the structure.

Bell Ringer 9/9/15Record the formulas for converting Celsius

to Fahrenheit, Fahrenheit to Celsius, Celsius to Kelvin and Kelvin to Celsius in

your composition books.

Neon has a boiling point of 27 K. Express this temperature in degrees Fahrenheit.

A) 352°F B) 168°F C) −246°F D) −411°F

Exit Closing 9/9/15

Bell Ringer 9/10/15

Mass (g) Height (cm) Diameter (cm)

Cylinder A 15.560 5.1 1.2

Cylinder B 35.536 5.9 1.3

Apply the COAST framework to End of Chapter Question #86 and answer parts (a) and (b). We will discuss the

answer at the end of the class.

Exit Closing 9/10/15

Mass (g) Height (cm) Diameter (cm)

Cylinder A 15.560 5.1 1.2

Cylinder B 35.536 5.9 1.3

Apply the COAST framework to End of Chapter Question #86 and answer parts (c) and (d).

Be prepared to share 1 of the 4 parts with the class.

Collect and Organize For this problem we try to identify which cylinder is made of aluminum and which is made of titanium by comparing experimentally determined densities with the known densities. Analyze(a) To calculate the volume of each cylinder from its dimensions, we will have to use the equation for volume of a cylinder: (b) To calculate the volume from the water displacement method, we need only find the difference in water volume for each cylinder from the diagram in Figure P1.86.(c) To determine the method with the most significant figures, we will compare the answers in parts a and b.(d) To compute the density for each cylinder, we use the equation for density: 

Bell Ringer 9/11/15

Apply the COAST framework to answer the following question.

Deepwater Horizon Oil Spill According to the U.S. government, 4.9 billion barrels of crude oil flowed

into the Gulf of Mexico following the explosion that destroyed the Deepwater Horizon drilling rig in April, 2010. Express this volume of crude oil in liters and in

cubic kilometers. (1 barrel of oil = 42 gallons.)

Collect and Organize We are asked in this problem to convert 4.9 billion barrels of crude oil to liters and cubic kilometers. AnalyzeThis is a conversion problem for which we will need the following conversion factors:

Think about ItThe oil gushed in this spill for 87 days—that is 9.0 109 L/day.

Exit Closing 9/11/15We 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 9/14/15

Quiz Day!

You have 3 minutes to make sure your Composition Book has all the information you might need in it. It is fair game to use

on your quiz!

Exit Closing 9/14/15

If there was one question on the quiz you feel like you were the best at put a star on the board next

to that question.

If there was one question on the quiz that was your weakness or the weakness of your

classmates, put a heart by it (no reason for the heart besides to see your heart drawing skills).

Bell Ringer 9/15/15You will be making a flip book with the next 5 sheets in your

composition book for chapter 2 INSTEAD of Cornell Notes. Yes it is graded. Please turn your book sideways. You will need to cut

the pages to look like the following:

Historical View of Atoms, Ions & Molecules

Cut the Black Lines through these 4 sheets.

Cut SMALL amounts off the top 4 pages to make tabs. Cut too much & you won’t have writing room! I suggest starting cutting with page 4 & work upward.

Exit Closing 9/15/15

Two of the following are a truth and the other is a falsehood. Evaluate each statement to determine which is which and be prepared to share with the class.

1) Robert Millikan determined the size and mass of the electron.

2) Robert Millikan’s oil drum experiment led to the plum pudding model.

3) JJ Thomson discovered the electron using a cathode ray.

Bell Ringer 9/16/15Had the plum-pudding model been valid, how would the results of the gold-foil experiment have differed from what Geiger and Marsden

actually observed?

Collect and Organize We are asked to consider what Rutherford’s gold-foil experiments would have shown if the plum-pudding model had been valid. AnalyzeThe plum-pudding model of the atom viewed the electrons as small particles in a diffuse, positively charged “pudding.” SolveHad the plum-pudding model been valid, the particles would have encountered only a diffuse positive charge when entering the atom, and they would have been only slightly deflected from their straight-line path. Think about ItBecause the positive charge in the atom was viewed as diffuse, no particles would have bounced back toward their source in an experiment confirming the plum-pudding model. The key result of Rutherford’s experiment was that a few particles came directly back toward the source, indicating a highly dense nucleus of positive charge.

Exit Closing 9/16/15

Nearly all stable nuclides have at least as many neutrons as protons in their nuclei. Which very

common nuclide is an exception?

Collect and Organize Given that most stable nuclides have at least equal numbers of neutrons in their nuclei as protons (and often more), we are to identify the element to which this rule is an exception. AnalyzeNeutrons help stabilize the nucleus by counteracting the repulsive forces between protons. SolveHydrogen, with only one proton, does not need neutrons to be stable and so is the exception. Think about ItHydrogen, however, can have one (for deuterium) and even two (for tritium) neutrons in its nucleus.

Bell Ringer 9/17/15

Describe two ways in which particles and β particles differ.

Needs some hints? You will be provided some visuals after 2

minutes. You should note that there are many more than 2 differences!

Collect and Organize We are to describe two differences between and particles. AnalyzeBoth and particles are the result of nuclear processes, but they differ in their masses and charges. SolveAlpha particles are massive (about the mass of the helium nucleus), whereas particles are very light (about the mass of an electron). These particles also have opposite charges: particles have a 2+ charge, whereas particles have a 1– charge. Think about ItAlpha particles are composed of two protons and two neutrons, and so when they are emitted from a nucleus the mass of the nuclide goes down by two mass units and its atomic number is reduced by 2. Beta emission changes a neutron into a proton in the nucleus, and therefore the atomic number increases, but the mass of the nuclide changes very little.

Exit Closing 9/17/15

How many protons, neutrons, and electrons are there in the following atoms?

(a) 11B; (b) 19F; (c) 131I; (d) 222Rn

Atom Mass Number

Atomic Number = Number of Protons

Number of Neutrons = Mass Number – Atomic Number

Number of Electrons = Number of Protons

(a) 11B 11 5 6 5

(b) 19F 19 9 10 9

(c) 131I 131 53 78 53

(d) 222Rn 222 86 136 86

An isotope is given by the symbol ZAX, where X is the element symbol from the periodic table, Z is the atomic number (the number of protons in the nucleus), and A is the mass number (the number of protons and neutrons in the nucleus). Often, Z is omitted because the element symbol gives us the same information about the identity of the element. To determine the number of neutrons in the nucleus for each named isotope, we subtract Z (number of protons) from A (mass number). If the elements are neutral (no charge), the number of electrons equals the number of protons in the nucleus.

Bell Ringer 9/18/15

Symbol 37Cl– ? ? ?

Number of Protons ? 11 ? 

88

Number of Neutrons ? 12 46 ?

Number of Electrons ? 10 36 

86

Mass Number ? ? 81 226

Fill in the missing information in the following table of monatomic ions.

How many molecules are there in 24 grams of FeF3?

How many molecules are there in 9.34 grams of LiCl?

How many grams do 4.3 x 1021 molecules of UF6 weigh?

Exit Closing 9/18/15

Phosgene was used as a chemical weapon during World War I. Despite the name, phosgene

molecules contain no atoms of phosphorus. Instead, they contain atoms of carbon and the group 16 element in the second row of the periodic table and the group 17

element in the third row. What are the identities and atomic numbers

of the two elements?

Collect and Organize Knowing that the chemical weapon phosgene contains a second-row element in group 16 and a third-row element in group 17 as well as carbon, we are to name those particular elements and give their atomic numbers. AnalyzeThe second-row elements start with lithium and end at neon. The third-row elements start at sodium and end at argon. SolveThe elements in phosgene besides carbon are oxygen (group 16), with atomic number 8, and chlorine (group 17), with atomic number 17. Think about ItPhosgene is a small molecule (COCl2) that is highly toxic and causes suffocation when inhaled.

Bell Ringer 9/21/15

Swimming Pool Chemistry Compounds containing chlorine have long been used to disinfect the water in swimming pools,

but in recent years a compound of a less corrosive halogen has become a popular

alternative disinfectant. What is the name of this fourth-row element?

Collect and Organize We are asked to name the fourth-row halogen that can be used as an alternative to chlorine as a disinfectant.

AnalyzeThe fourth-row elements start at potassium and end at krypton. The halogens are the elements in group 17. SolveThe fourth-row halogen element is bromine. Think about ItIodine, the fifth-row halogen, can also be used as a disinfectant or antiseptic.

We pee in the pool, leave our band aids, don’t wipe well and blow boogers for chlorine to disinfect!

Exit Closing 9/21/15Explain how percent natural abundances are

used to calculate average atomic masses.

Collect and Organize In this question we relate the percentage of natural abundance to the average atomic mass of an element. AnalyzeThe natural abundance of an isotope of an element indicates how common that isotope is in nature (on Earth). SolveIsotopic abundances are used to compute the weighted average atomic mass. The known isotopic abundances must be considered since the dominance of one isotope will contribute most to the average mass. Think about ItThe high abundance of one isotope over another indicates its higher nuclear stability.

Bell Ringer 9/22/15

The vanadium in nature consists of two isotopes: 50V and 51V.

Which one is the more abundant?

Collect and Organize Given the mass numbers (50 and 51) for the two isotopes of vanadium, we are to determine which is most abundant. AnalyzeThe atomic mass on the periodic table for vanadium is 50.942 amu. This value is closer to 51 than to 50. Solve51V is the more abundant isotope. Think about ItIn Appendix 3 you can see that 51V is actually 99.750% abundant, so 50V is only 0.250% abundant.

Exit Closing 9/22/15

Rank the following molecules based on decreasing molecular mass. (a) H2; (b) Br2; (c)

NO2; (d) C2H2; (e) BF3

Collect and Organize For a list of five compounds, we are to determine their molecular masses and then rank them in order of decreasing mass. AnalyzeWhen we use the masses on the periodic table to calculate the molecular masses, we obtain the following:H2 = 2.016 amu

Br2 = 159.81 amu

NO2 = 46.01 amu

C2H2 = 26.04 amu

BF3 = 13.83 amu

SolveIn order of decreasing molecular mass: (b) Br2 < (c) NO2 < (d) C2H2 < (e) BF3 < (a) H2.

Think about ItIn this problem fewer significant figures were necessary for the molecular masses because we were going to compare masses, and the masses were not likely to be too close together to warrant more than four significant digits.

Bell Ringer 9/23/15

Day 1 of 3 Density of an Egg Lab

I. Procedures…detailed by simplified (should have prediction prior to starting)

II. Safety-MSDS is a good resourceIII. Data/Observation Table ready for collectionIN PEN…Partners are fine to this point

Bell Ringer 9/24/15Day 2 of 3 Density of an Egg Lab

Before you can begin collecting data…you must have your lab book entry preapproved. Must be completed through safety before you can begin.Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

Bell Ringer 9/25/15

Day 3 of 3 Density of an Egg Lab

Last Day in Class…Grading on Monday!

Intro (last sentence is prediction), Procedures, Safety, Data & Observations, Calculations & Results (excel graphs et), Discussion of Results, References in ACS and Additional Questions

3rd Person Only! Individual work!

Bell Ringer 9/28/15

In what way is the molar mass of an ionic compound the same as its formula mass, and in

what ways are they different?

Collect and Organize For an ionic compound, we are asked to distinguish between its molar mass and its formula mass. AnalyzeThe molar mass is the mass of 1 mol of the particles that compose a substance, and the formula mass is the mass of one formula unit of an ionic compound. SolveBoth terms give us the mass of 1 mol of a substance. The distinction lies in the fact that the formula mass is reserved for the mass of a mole of a substance that does not have a defined molecular structure, such as ionic compounds held together by the attraction of the negative anions for the positive cations. Think about ItFor a molecular compound, the formula mass is equal to the molecular mass. These terms are often used interchangeably.

Exit Closing 9/28/15

The following quantities of trace gases were found in a 1.0 mL sample of air. Calculate the

number of moles of each compound in the sample.

a. 1.4 1013 molecules of H2

b. 1.5 1014 atoms of Hec. 7.7 1012 molecules of N2O

d. 3.0 1012 molecules of CO

Collect and Organize In this exercise, we convert the number of molecules of each gas found in the sample to moles. AnalyzeTo convert the number of molecules to moles, we divide by Avogadro’s number. Solve(a)

(b)

(c)

(d)  Think about ItThe trace gas that has the largest number of atoms or molecules present also has the largest number of moles present. In this sample of air, the amount of the trace gases decreases in the order He > H2 > N2O > CO.

13112

223

1.4 10 molecules of H2.3 10 mol H

6.022 10 molecules/mol

1410

23

1.5 10 atoms of He2.5 10 mol He

6.022 10 atoms/mol

12112

223

7.7 10 molecules of N O1.3 10 mol N O

6.022 10 molecules/mol

1212

23

3.0 10 molecules of CO5.0 10 mol CO

6.022 10 molecules/mol

Bell Ringer 9/29/15Today we will have a BR, a Middle Q, and Exit Closing…

How many moles of iron and how many atoms of iron are there in 2.5 moles of each of the following? (a) wolframite, FeWO4; (b) pyrite, FeS2; (c) magnetite, Fe3O4; (d) hematite, Fe2O3

Collect and Organize In this exercise we convert from the moles of iron contained in a substance to the number of atoms present.AnalyzeFor each substance we need to take into account the number of moles of iron atoms present in 1 mol of the substance. For 2.5 mol of substance, then, a substance that contains two atoms of iron in its formula contains 2.5 2 = 5.0 mol of iron. We can then use Avogadro’s number to convert the moles of iron to the number of atoms present in the sample.Solve(a) Wolframite, FeWO4, contains one atom of Fe per formula unit, so 2.5 mol of wolframite contains 2.5 mol of Fe.

(b) The formula for pyrite, FeS2, contains only one iron atom per formula unit as well, so the answer is identical to that calculated in part a.

(c) Magnetite, Fe3O4, contains three iron atoms in its formula, so 2.5 mol of Fe3O4 contains 2.5 3 = 7.5 mol of iron. (d) Hematite, Fe2O3, contains two iron atoms in its formula, so 2.5 mol of hematite contains 2.5 2 = 5.0 mol of iron.Think about ItThe ratio of iron atoms in wolframite to pyrite to magnetite to hematite of 1: 1: 3: 2 reflects the number of iron atoms in their formulas.

The Middle! 9/29/15

Which substance in each of the following pairs of quantities contains more moles of oxygen?

a. 2 mol N2O or 1 mol N2O5

b. 1 mol NO or 1 mol Ca(NO3)2

c. 2 mol NO2 or 1 mol NaNO2

Collect and Organize Given the formulas and the moles of each substance in a pair, we are asked to decide which compound contains more moles of oxygen. AnalyzeTo answer this question, we have to take into account the moles of oxygen present in the substance formulas as well as the initial number of moles specified for each substance. Solve(a) Two moles of N2O contains 2 mol of oxygen, and 1 mol of N2O5 contains 5 mol of oxygen. Therefore, N2O5 contains the most moles of oxygen.

(b) One mole of NO contains 1 mol of oxygen, and 1 mol of calcium nitrate [Ca(NO3)2] contains 6 mol of oxygen. Therefore, the calcium nitrate contains six times more moles of oxygen than the NO.(c) Two moles of NO2 contains 4 mol of oxygen, and 1 mol of sodium nitrite (NaNO2) contains 2 mol of oxygen. The NO2 contains more moles of oxygen.

Think about ItWe cannot decide which substance has more moles of oxygen by comparing only the amounts of substances present. If that were the case, we would have concluded wrongly that 2 mol of N2O contains more moles of oxygen than 1 mol of N2O5.

Exit Closing 9/29/15What nuclide is produced in the core of a collapsing giant star by each of the following reactions?

a. 6529Cu + 3 1

0n → ? + –10β

b. 6830Zn + 2 1

0n → ? + –10β

c. 8838Sr + 1

0n → ? + –10β

Collect and Organize We are asked to predict the products of neutron capture reactions in the core of a collapsing giant star.

AnalyzeTo solve this problem, we balance the reactions for mass number and atomic number between the reactants and products. We have to take into account that multiple neutrons can be added under these conditions. Solve(a)

(b)

(c)  Think about ItAdding neutrons to the nucleus does not itself change the atomic number. Subsequent emission, however, does, and the result is the building up of heavier elements in the periodic table.

Bell Ringer 9-30-15

Please have your 6 essay quiz questions stapled with the cover sheet. Be prepared to write a question selected by the roll of our dice. You

may have out your learning log but not your book.

Good Luck!

Bell Ringer 10/1/15

Chapters 1 & 2 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!