Academic Chemistry Chemical Quantities - PBworks · Academic Chemistry Chemical Quantities Homework On-Time LATE DATE ASSIGNMENT 100 70 ... It even has 62 grams of amazing

Unit 6 Periodic Table

20 cincochem.pbworks.com Chemical Quantities

Somewhere, something incredible is waiting to be known. Carl Sagan

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Name _______________________________ Academic Chemistry

Chemical Quantities

Homework On-Time LATE DATE ASSIGNMENT 100 70

6.1

6.2

6.3

6.4

6.5

6.6

6.7

WARMUP Unit 6


Day 1

Day 2

Day 3

Day 4

Day 5

Day 6

Resources

Chemical Quantities cincochem.pbworks.com 19

Common Polyatomic Ions List

Name Ion Name Ion acetate C2H3O2

– or CH3COO– hypochlorite ClO– ammonium NH4

+ nitrate NO3–

carbonate CO32– nitrite NO2

– chlorate ClO3

– perchlorate ClO4–

chlorite ClO2– permanganate MnO4

– chromate CrO4

2– phosphate PO43–

cyanide CN– phosphite PO33–

dichromate Cr2O72– silicate SiO3

2– hydrogen carbonate HCO3

– sulfate SO42–

hydroxide OH– sulfite SO32–

How to key scientific notation into a TI calculator:

Type in 6.02 x 1023: Should display: How to key molar mass into a TI calculator in ONE STEP!: Example: Na2SO4 Mole conversion chart

Roman Numerals for Transition Metals 1‐6

1 = I 2 = II 3 = III 4 = IV 5 = V 6 = VI

20 Common Polyatomic Ions

Mass Grams

Representative Particles Atoms, Molecules, Formula Units

MOLES

Molar Mass 6.02 10

Warmups


Day 7

Day 8

Day 9

Day 10

Day 11

Day 12

Molar Mass Homework 6.1


Find the molar mass of the compound. Round average atomic mass to the hundredths place. Show units.

1. NaCl 2. Ca(OH)2

Na = __________ Ca = __________

Cl = ___________ O = __________

NaCl = __________ H = __________

Ca(OH)2 = ___________

3. Fe2O3 4. Ammonium phosphate

5. Al2(SO4)3 6. Dinitrogen trioxide

7. An alien visits earth. He brings with him an unknown substance. He says, “I believe this substance is like an Earthly compound; it is either like nitrogen dioxide or nitrogen trioxide. I’m not sure which. All I know is that its molar mass is 62.01 g.” Which compound did the alien bring with him? Show your work to receive credit.

Homework 6.2 Conversions - Mass


Complete the following conversions using dimensional analysis. Show work! 1. Convert 0.780 mol of calcium cyanide, Ca(CN)2, to mass.

2. How many grams are in 0.50 mol of copper (II) sulfate?

3. Convert 30 g of silicon dihydride to moles.

4. How many moles are in 100 grams of potassium sulfide?

Mixed Questions Extra Practice


3. Many teenage females are anemic (they don’t have enough iron in their blood). The FDA recommends that teenage girls consume at least 1.617 x 1020 atoms of iron daily. How many grams is this?

One steak contains 0.0043 grams of iron. If Sasha eats one steak per day (and no other iron), will she get enough iron?

4. Find the molar mass of calcium sulfite.

5. What is the mass of 1.94 mol of dinitrogen pentoxide?

6. How many moles are in 205 g of carbon tetrachloride?

7. How many moles are in 7.21 x 1025 formula units of barium chloride

Extra Practice Mixed Questions


1. Your mom asks you to put away the leftovers after dinner. You ask her, “What should I use?” She replies, “Use 3.5 moles of aluminum foil, of course!” How many atoms of aluminum foil should you use?

2. Nicki Minaj plans to throw the wildest New Year’s Eve concert ever,

and in doing so plans to have a huge bubbling cauldron, so she asks you, her manager, to make it happen. To maintain bubbling for the entirety of her 38 minute concert you will need 3060.1 moles of dry ice, or frozen carbon dioxide. How many grams of dry ice do you need? Packages of dry ice come in increments of 500 grams. How many packages do you need to purchase?

Conversions - Mass Homework 6.2


5. Your grandfather has to take 5 grams of aspirin (C8H8O4) daily for his arthritis. How many moles of aspirin should he take?

6. You go to the pawn shop to buy your girlfriend some jewelry. The clerk offers to sell you a necklace that has 5 grams of gold in it for $300. How many moles of gold are in the necklace?

7. You are conducting a lab experiment to evaluate the reaction between calcium hydroxide and hydrochloric acid. Your teacher has told you how much of each reactant to use (in moles). You must convert to mass before you can start. Complete the table.

Name of Compound

Formula of Compound

Molar Mass Moles Needed Mass Needed

calcium hydroxide 2.0 mol

hydrochloric acid 4.0 mol

Homework 6.3 Conversions - Particles


Complete the following conversions using dimensional analysis. Show work!

1. How many moles are in 1.50 x 1023 molecules of nitrogen trihydride?

2. Convert 4.8 moles of calcium carbonate to formula units.

3. How many molecules are in 4.80 x 10–3 mol bromine gas?

4. There are ___ moles in 3.73 x 1022 formula units of barium chloride.

Molecular Formula Homework 6.7


3. Elaidic acid is the primary trans fatty acid present in partially hydrogenated oils used in food production. Calculate the molecular formula for elaidic acid given that it has an empirical formula of C9H17O1 and a mass of 282 g/mol.

4. Strychnine, a deadly poison, has a mass of 334 amu and a percentage composition of 75.42% carbon, 6.63% hydrogen, 8.38% nitrogen, and 9.57% oxygen. What is the molecular formula of strychnine?

Homework 6.7 Molecular Formula


Answer the following questions concerning molecular formulae. Use the steps outlined in your notes.

1. Find the molecular formula for a compound with a molar mass of

90.04 g/mol and an empirical formula of CHO2. Step 1:

Step 2:

Step 3:

2. Find the molecular formula for a compound with 46.68% nitrogen and 53.32% oxygen and a molar mass of 60.01 g/mol.

Conversions - Particles Homework 6.3


5. Your doctor prescribes you lithium carbonate for your bipolar disorder. Examine the prescription below.

How many formula units of lithium carbonate will you ingest each day?

6. The same pawn shop clerk from HW 6.2 says, “Okay, you don’t like that necklace? How about these earrings? They have 1.00 x 1025 atoms of gold in them!” How many moles of gold is this?

7. A cold pack uses an endothermic reaction to cool its surroundings. Inside a

cold pack are 5.33 x 1024 formula units of ammonium nitrate. How many moles of ammonium nitrate are in a cold pack?

Dr. Emilio Avogadro Date Oct 23, 2012

Patient: Kim Estudiante ℞: Take 5 mol Lithium Carbonate

Once daily at bedtime

Signature E. Avogadro

Homework 6.4 Conversions - Mixed


Complete the following conversions using dimensional analysis. Show work! 1. Convert 3.33 x 1024 atoms of sodium to grams.

2. There are ____ moles in 187 g aluminum.

3. How many grams are in 40 moles of ammonium chloride? 4. How many moles are in 333 g tin (II) fluoride?

Empirical Formula Homework 6.6


3. Sodium sulfite is a meat preservative and sodium sulfate is a laxative. Your grandmother gives you a side of beef for your birthday and you’d like to keep it from rotting. You’ve found a sample of a compound of sodium that contains 36.5 grams of sodium, 25.4 grams of sulfur, and 38.1 grams of oxygen. Do you have a laxative or the meat preservative you so desperately need?

4. As lead arson investigator with the Houston Fire Department you find a small sample of the accelerant (fuel) that caused a fire that took the lives of 11 people in an urban apartment complex. You run the sample through a mass spectrometer and find that it contains 37.5% carbon, 12.5% hydrogen, and 50.0% oxygen, by mass. Determine the empirical formula of this substance.

Homework 6.6 Empirical Formula


Answer the following questions concerning empirical formulae. Use the steps outlined in your notes. 1. Determine the empirical formula for a compound containing 19.55

grams potassium and 4.00 grams oxygen.

Step 1 –

Step 2 –

Step 3 ‐

2. A compound contains 174.86 grams of iron and 74.14 grams of oxygen. Construct the empirical formula.

Conversions – Mixed Homework 6.4


5. Convert 5.00 x 1025 molecules hydrogen (H2) to grams.

6. In 1970, Nobel Prize winning scientist Linus Pauling recommended taking “megadoses” of vitamin C to ward off the common cold. He suggested taking up to 2.5 grams per day. How many molecules of vitamin C (C6H8O6) did he recommend that you should take per day?

7. Have you ever tried the energy drink Crunk!!!? It’smade by Lil’ Jon

(the rapper) and it is so yummy! It even has 62 grams of amazing sugar (C12H22O11) per can! That’s like _________ molecules of sugar!

Homework 6.5 Percent Composition


1. Write the formula for percent composition below. Use the formula and the information given in subsequent questions to complete this assignment. % composition = x 100%

2. Find the percent composition of hydrogen in each compound:

a) Ca(OH)2 % of H = __________

b) C2H6 % of H = __________

c) Al (C2H3O2)3 % of H = __________

3. Find the percent composition of each element in these compounds:

a) NaCl molar mass = __________

% of Na = __________

% of Cl = ___________

b) (NH4)2S molar mass = __________

% of N = __________

% of H = __________

% of S = __________

Percent Composition Homework 6.5


4. A sample of liquid with a mass of 8.657 grams was decomposed into its elements and gave 5.217 grams of carbon, 0.9620 grams of hydrogen, and 2.478 grams of oxygen. What is the percent composition of this oxygen in this compound? (hint: you don’t need to calculate molar mass to solve this problem, just use the formula from question #1)

5. A quantitative analysis of 0.4620 grams of an unknown solid found 0.1945 grams of carbon, 0.02977 grams of hydrogen and 0.2377 grams of oxygen. Calculate the percent composition of carbon in this compound. (hint: you don’t need to calculate molar mass to solve this problem, just use the formula from question #1)

6. What is the percentage of Fe in FeCO3 ?

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Academic Chemistry Chemical Quantities - PBworks · Academic Chemistry Chemical Quantities Homework On-Time LATE DATE ASSIGNMENT 100 70 ... It even has 62 grams of amazing