PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
Here we go with round two, kids. We’ll continue with a little light review and some sneak-peek applications of the stuff we’ve done and how it pertains to new topics. For our dear parents and students, we’ve included the solutions for you all to check back on. Don’t feel like it is wrong to review the solutions. Maybe they can provide some feedback since we aren’t there to immediately provide it for you. We’ll be continuing the numbering of the packet from last week. So just keep going, one topic at a time. Everything you need will be provided on each page. Please email us if you have questions! We’re also adding a few supplementary links you may visit if you would like, but they are not required. We hope you are safe and surviving this temporary, new normal.
Much Zizzer Love to each of you and your families. Please be safe and stay well.
Topic 9 – Finding Molar Masses
Topic 10 – Percentage Composition Problems
Topic 11 – Naming Practice 2.0 – the trick to naming acids
Topic 12 – Electron Configurations
Topic 13 – Chemistry Trivia
Topic 14 – Writing Word and Formula Equations
Topic 15 – Balancing Equations
Topic 16 – Naming Simple Organic Compounds like Hydrocarbons
Please let us know if you need anything! Have fun!!
Ms. Henderson and Ms. Kinder.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
Topic 9 – Finding Molar Masses
These problems will get increasingly more difficult as you move through this lesson. Use the periodic table provided to calculate the molar masses of the compounds in question. The first one has been done for you. Units are g/mol; round to the nearest hundredths place.
1. Find the molar mass of Silicon dioxide (SiO2) Step 1 – Count stuff out (Si = 1 O = 2) Step 2 – Find the masses and multiply by the number present (Si = 1 x 28.09; O = 2 x 16.00) Step 3 – Add the values (28.09 + 32.00 = 60.09 g/mol)
2. Find the molar mass Potassium selenide (K2 Se)
3. Find the molar mass of Dinitrogen tetroxide (N2O4)
4. Find the molar mass of Cobalt (II) phosphate.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
5. Find the molar mass of benzene (C6H6)
Topic 10 – Percentage Composition Problems
The Laws of Definite and Multiple Proportions support that compounds have unique compositions even if they are composed of similar elements. Use the periodic table to find the percentage composition of each of the following compounds. The problems get more difficult as you go. The fist problem has been completed for you. Units should be % of each element and please round to the hundredths place.
1. Find the percentage composition of Magnesium hydroxide (Mg (OH)2) Start by finding the molar mass (review the previous lesson) 58.32 g/mol Then divide out each element and multiply by 100. (24.30/58.32) x 100 = 41.67% Mg; (32.00/58.32) x 100 = 54.87% O; (2.02/58.32) x 100 = 3.46% H Check your work to be sure your solutions are close to 100 when you add them
2. Find the percentage composition of Uranium hexafluoride.
3. Find the percentage composition of Phosphorus pentachloride.
4. Find the percentage composition of Ammonium nitrate.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 5. A certain compound found in caves and shells has a mass of 74.10 g/mol. It is 54.09% Ca, 2.73% H, and the remainder is oxygen. Give the scientific name and formula for this compound.
Topic 11 – Naming Practice 2.0 (the trick to naming acids) Here’s the short version – acids form when certain compounds dissolve in water and donate hydrogen ions to solution so they become more concentrated. Imagine each of these items in this table are compounds dissolved in water. Some release H+ and a halide, like Cl-. Some - release one or more hydrogen ions and oxyanions like ClO3 . Problem… Figure out the pattern for naming these acids… Two Tasks
Common Binary Acids and Oxyacids
HF Hydrofluoric acid HNO2 Nitrous acid HClO Hypochlorous acid HCl Hydrochloric acid HNO3 Nitric acid HClO2 Chlorous acid HBr Hydrobromic acid H2SO3 Sulfurous acid HClO3 Chloric acid HI Hydriodic acid H2SO4 Sulfuric acid HClO4 Perchloric acid H3PO4 Phosphoric acid CH3COOH Acetic acid H2CO3 Carbonic acid
Using what you remember about ions
Organize the acids in the table above into two categories….
1. Oxyacids 2. Binary Acids
Why did you decide to place the acids into each list?
Identify the pattern for prefixes and suffixes on each acid based on the ions present…
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
Topic 12 – Electron Configurations
Will it never end???? Using the periodic table, answer each of the following questions.
1. Identify the element found in Group 2, Block s, Period 5. ______2. Identify the element found in Group 4, Block d, Period 4. ______3. Give the atomic number for the element with the valance configuration of 6s2 6p4. ______4. Give the symbol for the element whose Noble gas configuration is [Ar] 4s2 3d5. ______5. Give the electron configuration for seaborgium.
6. Give the Noble gas configuration for atomic number 56.
7. Give the orbital notation for cobalt.
8. Give the group, block and period for bromine.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
9. Find the error(s): 1s22s22p63s23p64s23d104p65s24d105p86s26d10 (If I was trying to write the electron configuration for mercury, what mistake(s) did I make?)
10. Give the Noble gas configuration for mercury.
Topic 13 – Chemistry Trivia
Today’s an easy(ish) day in pseudochemistry class. Try your hand at a little fancy chemistry trivia just for fun! Check your work and see how you do.
Matching Mayhem!! I may have given you more choices than clues and wait for it – you might use a few of them more than once. Have fun.
A. C8H10N4O2 J. Vitamin B. John Dalton K. Organic compound
C. Copernicus L. C8H11NO2 D. Amine group M. Polymer E. Ascorbic acid N. Monomer F. Deoxyribonucleic acid O. Nitrogen G. Democritus P. Physical chemistry H. Molar mass Q. Metallurgy I. Multiple proportions
1. _____ a law written to sort compounds with common elements by mass, like CO2 and CO 2. _____ the formula for caffeine 3. _____ a general class of compound that contains carbon 4. _____ the part of a protein backbone that is alkaline 5. _____ “atomos” 6. _____ “vital amine” 7. _____ without this you may end up with a “touch of the scurvy” 8. _____ heliocentric solar system 9. _____ “many parts” 10. _____ wrote the atomic theory 11. _____ namesake for atomic number 112 12. _____ makes your pupils dilate when you see your crush 13. _____ study of bronze 14. _____ “the laughing one” 15. _____ identifying amount of substance 16. _____ orange juice 17. _____ nitrogen and hydrogen 18. _____ an amino acid is one
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 We’ll that was fun. More to come!
Topic 14 – Writing Word and Formula Equations
Today’s lesson is short. As you get better and better at writing and balancing equations you can skip this part, but for now, let’s practice going from the sentence provided to a word equation first, then to a formula or skeleton equation. A skeleton equation is just one that hasn’t been balanced. I’ll work the first one for you. They get a little tougher at the end.
Reactant(s) → Product(s)
1. Methane reacts with oxygen to produce carbon dioxide and water. - Methane + oxygen carbon dioxide + water
- CH4 + O2 CO2 + H2O
2. Sodium iodide reacts with fluorine to produce iodine and sodium fluoride.
3. Lithium hydroxide and hydrochloric acid (HCl) produce water and the salt, lithium chloride.
4. Sodium permanganate (NaMnO4) is left in solution when sodium reacts with calcium
permanganate (Ca(MnO4)2) leaving calcium to settle out as a precipitate.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 5. Magnesium reacts with dissolved aluminum phosphate to form aluminum and magnesium phosphate.
6. Octane gas (C8H18) combusts in oxygen to form carbon dioxide and water.
Topic 15 – Balancing Equations
Remember to count out each atom on both sides of the equation then add coefficients until you get them to balance with the law of conservation of mass. Today’s task s to balance the equations from yesterday.
- Important hints o Don’t forget the diatomic 7 (H2, N2, O2, F2, Cl2, Br2, and I2) these always appear in pairs of atoms as molecular elements o Keep big polyatomic ions together if they appear on both sides of the equation, you can count the atoms separately if you want but start by trying to match the big guys. o Metals can appear as single atoms, like Al, Cu, or Ca. No subscripts needed. o You’ve got to start with the right formulas!!
Reactant(s) → Product(s)
1. Methane reacts with oxygen to produce carbon dioxide and water. - Methane + oxygen carbon dioxide + water
- CH4 + 2O2 CO2 + 2H2O C = 1 O = 2 4 C = 1 H = 2 4 H = 4 O = 2 O = 1 2
2. Sodium iodide reacts with fluorine to produce iodine and sodium fluoride.
3. Lithium hydroxide and hydrochloric acid (HCl) produce water and the salt, lithium chloride.
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
4. Sodium permanganate (NaMnO4) is left in solution when sodium reacts with calcium
permanganate (Ca(MnO4)2) leaving calcium to settle out as a precipitate.
5. Magnesium reacts with dissolved aluminum phosphate to form aluminum and magnesium phosphate.
6. Octane gas (C8H18) combusts in oxygen to form carbon dioxide and water.
Topic 16 – Naming Simple Organic Compounds like Hydrocarbons
Hydrocarbons are familiar, covalent compounds that store energy. They are nonpolar and can take on different forms as temperature and pressure change. Happily, they all “combust”. Today you’ll try to name some and find some patterns. Round 1 – Prefixes [Prefixes will indicate how many carbons are found in the backbone, you’ll recognize some of these, go with it.] Complete the table.
Prefix meth eth prop but pent hex hept oct non dec Carbon # 2 3 6 9
Do you see any subtle differences between these and our other prefixes used in naming covalent compounds? ______
Round 2 – Suffixes [Suffixes will also start to sound familiar; these indicate numbers of bonds between carbons.]
Suffix Meaning -ane All single bonds -ene At least one double bond -yne At least one triple bond
Yes. – This is as straight forward as it seems, combine the two word parts and you’ve got the basic naming trend. Try it out, the first one is done for you: 1. Four carbons, all single bonds - butane 2. Three carbons, all single bonds ______3. Five carbons, one triple bond ______
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 4. Eight carbons, all single bonds ______5. Six carbons, one triple bond ______6. Two carbons, one triple bond ______7. Propene has ______8. Butyne has ______9. Pentane has ______10. Decyne has ______Easy Enough. Now what do you do if you aren’t given the formula…. Google it! No. You’re smarter than that. Here’s the plan. Next time, let’s see if we can derive a formula for working that out sans the Google on the internet machine. Cool – until next time!! Good job!
Solutions by Topic We’re providing the solutions again so you can test your knowledge. We want you all to check your work. If you get stuck or don’t understand what we’re asking for glance at a solution and see if it gives you a clue. Follow through and check your work! Good luck. One day at a time. Topic 9 – Finding Molar Masses
1. SiO2 = 60.09 g/mol 2. K2Se = 157.16 g/mol 3. N2O4 = 92.02 g/mol 4. Co3(PO4)2 = 366.73 g/mol 5. C6H6 = 78.12 g/mol Topic 10 – Percentage Composition Problems 1. 41.67% Mg, 3.46% H, 54.87% O 2. 67.60% U, 32.40% F (UF6) 3. 14.87% P, 85.1% Cl (PCl5) 4. 35.00% N, 5.05% H, 59.96% O (NH4NO3) 5. Ca (OH)2 – calcium hydroxide [find missing oxygen at 43.18% - then work your way back a piece at a time.] 푋 푔 퐶푎 푥 100 = 54.09% , x = 40.08 g or one atom of Ca 74.10 Topic 11 – Naming Practice 2.0 1. All the oxyacids have three or atoms and contain an oxyanion. (there are 11) 2. All the binary acids have two atoms and are hydrogen and a halogen. (4 listed)
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 Pattern – Binary (H – hydro; ion+ ending ic) Oxyacids Example set: HClO (take apart the compound – H+ and ClO-, hypochlorite to ous)
+ - HClO2 (take apart the compound – H and ClO2 , chlorite to ous)
+ - HClO3 (take apart the compound – H and ClO3 , chlorate to ic)
+ - HClO4 (take apart the compound – H and ClO4 , perchlorate to ic)
Topic 12 – Electron Configurations 1. Strontium 2. Titanium 3. 84 4. Mn 5. 1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p67s25f146d4 6. [Xe] 6s2 ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿⇂ ↿ ↿ ↿ 7. 1푠 2푠 2푝 3푠 3푝 4푠 3푑 8. Group 17 (7A), Block p, Period 4 9. Errors – 5p8, missing 4f14, used 6d10 instead of 5d10, miscount of electrons (too few) 10. [Xe] 6s2 4f14 5d10 Topic 13 – Chemistry Trivia 1. I 7. E 13. Q 2. A 8. C 14. G 3. K 9. M 15. H 4. D 10. B 16. E 5. G 11. C 17. D 6. J 12. L 18. N
Topic 14 – Writing Word and Formula Equations 1. Given
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020
2. Sodium iodide + fluorine iodine + sodium fluoride (NaI + F2 I2 + NaF) 3. Lithium hydroxide + hydrochloric acid water + lithium chloride
(LiOH + HCl H2O + LiCl) 4. Sodium + calcium permanganate calcium + sodium permanganate
(Na + Ca(MnO4)2 Ca + NaMnO4) 5. Magnesium + aluminum phosphate aluminum +magnesium phosphate
(Mg + AlPO4 Al + Mg3(PO4)2) 6. Octane + oxygen carbon dioxide +water
(C8H18 + O2 CO2 + H2O)
Topic 15 – Balancing Equations 1. Completed
2. (2NaI + F2 I2 + 2NaF)
3. (LiOH + HCl H2O + LiCl) *balanced
4. (2Na + Ca(MnO4)2 Ca +2 NaMnO4)
5. (3Mg +2AlPO4 2Al + Mg3(PO4)2)
6. (2C8H18 +25 O2 16CO2 +18H2O) Topic 16 – Naming Simple Organic Compounds like Hydrocarbons Table
Prefix meth eth prop but pent hex hept oct non dec Carbon # 1 2 3 4 5 6 7 8 9 10
Slight differences (mono/meth, di/eth, tri/prop, tetra/but (rest are the same) 1. Butane 2. Propane 3. Pentyne 4. Octane 5. Hexyne 6. Ethyne 7. 3 carbons, one double bond
PREAP / CHEMISTRY EXTENDED LEARNING 2, 2020 8. 4 carbons, one triple bond 9. 5 carbons, all single bonds 10. 10 carbons, one triple bond