Day 1: 1. Hand out syllabus and lab1.1 2. Syllabus - homework policy 3. Lab safety

Day 1:1. Hand out syllabus and Lab1.1

2. Syllabus- homework policy

3. Lab safety- signed safety contract due Friday

4. Begin Ch1

5. HW: Ch1 HW#1

Ch1 – Classification of MatterMatter – anything that occupies space and has mass.

States of Matter solid liquid gas (plasma)Volume: Shape:

Classification of MatterMatter – anything that occupies space and has mass.

States of Matter solid liquid gas (plasma)Volume: definite definite variable variably large Shape: definite variable variable variably large

Elements – simplest forms of matter (periodic table)ex: iron, aluminum, oxygen

Compounds – combinations of elements chemically attached to each otherex: NaCl (table salt), H2O, CH4 (methane)



Elements – simplest forms of matter (periodic table)ex: iron, aluminum, oxygen

Compounds – combinations of elements chemically attached to each otherex: NaCl (table salt), H2O, CH4 (methane)

MixturesHomogeneous mixture – substances mixed together that are the

same throughout.ex: air in this room, solutions

Heterogeneous mixture – substances mixed, not uniformex: salad, muddy water, atmosphere



How would you separate mixtures?


How would you separate mixtures?Properties of Matter

Physical Properties – deal with the physical state: solid, liquid, gas (table)ex: mass, volume, density, boiling point, melting point,

malleability (smash it), ductility (make into wire), etc.

These properties don’t change what the substance is

Physical Changes – change any of theseex: boil, freeze, condense, dissolve, break, split, creek, crush, etc.


How would you separate mixtures?Separate mixtures using physical properties. Exs: magnetism, solubility, density, filtration

distillation – the process of separation based on volatility (in a mixture, substance might vaporize at different temps)chromatography – mobile phases moving relative to stationary phases.


How would you separate a compound?


How would you separate a compound?Chemical Properties – deal with how a substance chemically reacts with

other substances.Chemical Change – substances transform into new substances with different

properties. Can’t easily be changed back.Evidence of Chemical Reaction:

1. Color change2. Gas produced3. Precipitate formed – solid comes out of the solution

Ex: AgNO3 (aq) + NaCl(aq) NaNO3 (aq) + AgCl (s)

reactants products

Particulate Models:

1. Physical Change:

2. Chemical Change:

Ch1 HW#1 p34+ 65,70 + Prelab1.1 Questions

Ch1 HW#1 p34+ 65,7065.Classify the each of the following as a mixture or a pure substance.

a) waterb) bloodc) the oceand) irone) brassf) uraniumg) wineh) leatheri) a solution of ethanol and water

65.Classify the each of the following as a mixture or a pure substance.a) water (distilled? then pure substance compound)b) blood (mixture. homo or hetero? IDK ask a bio)c) the ocean (mixture. hetero or homo?)d) iron pure substance - elemente) brass pure substance? (metallic compound, alloy of Cu and Zn)f) uraniumg) wineh) leatheri) a solution of ethanol and water

65.Classify the each of the following as a mixture or a pure substance.a) water (distilled? then pure substance compound)b) blood (mixture. homo or hetero? IDK ask a bio)c) the ocean (mixture. hetero or homo?)d) iron pure substance - elemente) brass pure substance? (metallic compound, alloy of Cu and Zn)f) uranium pure substance - elementg) wine mixture. home or hetero?h) leather good question – mixture?i) a solution of ethanol and water heterogeneous mixture

70. You are in Paris and went to buy some peaches for lunch. The sign in the fruit stand indicates that peaches are 11.5 francs per kilogram. Given that there are approximately 5 francs to the dollar, calculate what a pound of peaches will cost in dollars.

70. You are in Paris and went to buy some peaches for lunch. The sign in the fruit stand indicates that peaches are 11.5 francs per kilogram. Given that there are approximately 5 francs to the dollar, calculate what a pound of peaches will cost in dollars.

11.5 f 1 $ 1kg kg 5 f 2.2 lbs = 1.045 $/lb 1$/lb sig digs)

Ch2 Rev WS on Formulas and Naming (30 questions, we do 10, you do 20 as part of Ch2,3 Rev HW)

Lab1.1 Pre-Lab Questions + Go over lab procedure1. Explain the difference between a chemical and physical change.2. List three examples of physical changes and three examples

of chemical changes, and explain why you think these are chemical and physical changes.

(This would get a better score if it was spread out.) Kent Purser(You can find a template of this online.)

Lab1.1 – Chemical and Physical ChangesObjective: To observe various experiments and conclude whether the experiment was a chemical or physical change. (+1)Procedure: Conduct various experiments related to observable changes. (+1)Prelab Questions (+1 each) 1. 2.Data Tables (+5) Station Initial

Color(s)Color(s) of End Products

InitialTemp (oC)

FinalTemp (oC)

Observations Type of Change

Explanation

123

Graphs (none on this lab.) (+5) Temp (oC)

0:00 0:30 1:00 1:30 2:00Time (sec)

Conclusions (+2 each)1. :5. Total: 19 pointsFurther Investigations (none on this lab.) (+2 XC each!)

Ch3 Rev Periodic Table, Naming, the Mole, and EqnsThe periodic table has many secrets, including oxidation numbers. +1 0 +2 +3 +/-4 -3 -2 -1

( usually +2 )

The MoleAvogadro’s number: 6.02 x 1023 atoms per mole.

How did Avo come up with this random number?!?

Let’s pick on Carbon: How many portons and neutrons? _______

What is its molar mass? _______

The MoleAvogadro’s number: 6.02 x 1023 atoms per mole.

Molar Mass

Don’t forget to celebrate Mole Day!XC if you take a selfie … at 6:02pm on October 23 …

… with a cup of 18ml of water…

molg

- xx. 0.12 C mol 1 C atom 1 nucleon 1

atoms10022.6 nucleons 12 g10671 2324

Balancing EquationsEx1) In the Ostwald process, at 10000C, ammonia gas reacts with oxygen

gas to produce nitric oxide (NO(g)) and water vapor. Write and balance.

Ex1) In the Ostwald process, at 10000C, ammonia gas reacts with oxygen gas to produce nitric oxide (NO(g)) and water vapor. Write and balance.

4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g)

StoichiometryEx2) Lithium hydroxide is used in the space station to remove exhaled

carbon dioxide by forming solid lithium carbonate and water. What mass of carbon dioxide will be absorbed by 1.00 kg lithium hydroxide?

HW#79) Write a balanced chemical equation that describes each of the following.

a. Iron metal reacts with oxygen to form rust, iron(III) oxide.b. Calcium metal reacts with water to produce aqueous calcium hydroxide

and hydrogen gas.c. Aqueous barium hydroxide reacts with aqueous sulfuric acid to produce

solid barium sulfate and water.

Ch2,3 Rev HW Ch2 Rev WS + p125+ 79,80,86

Ch3 HW#3 p125+ 79,80,86 + Ch2 Rev WS79. Write a balanced chemical equation that describes each of the following.a. Iron metal reacts with oxygen to form rust, iron(III) oxide.b. Calcium metal reacts with water to produce aqueous calcium hydroxide and

hydrogen gas.c. Aqueous barium hydroxide reacts with aqueous sulfuric acid to produce solid

barium sulfate and water.

a) Fe + O2 Fe+3 O2- Fe2O3 4 Fe + 3 O2 2 Fe2O3

b) Ca + H2O Ca+2 OH-1 + H2 Ca(OH)2 + H2

Ca + H(OH) Ca(OH)2 + H2 Ca + 2H(OH) Ca(OH)2 + H2 c) Ba(OH)2 + H2SO4 BaSO4 + 2H(OH)

80. Give the balanced equation for each of the following chemical reactions. a. Glucose (C6H12O6) reacts with oxygen gas to produce gaseous carbon

dioxide and water vapor.

b. Solid iron (III) sulfide reacts with gaseous hydrogen chloride to form solid iron (III) chloride and hydrogen sulfide gas.

c. Carbon disulfide liquid reacts with ammonia gas to produce hydrogen sulfide gas and solid ammonia thiocyanate (NH4SCN).

86. Phosphorus occurs naturally in the form of fluorapatite, CaF2 3Ca(PO4)2, the dot indicating 1 part CaF2 to 3 parts Ca(PO4)2. This mineral is reacted with an aqueous solution of sulfuric acid in the preparation of a fertilizer. The products are phosphoric acid, hydrogen fluoride, and gypsum, CaSO4 2H2O. Write and balance the chemical equation describing this process.

CaF2 3Ca(PO4)2 + H2SO4 H3PO4 + HF + CaSO4 H2O


H2O+ CaF2 3Ca(PO4)2 + H2SO4 H3PO4 + HF+ CaSO4 H2O


2H2O+ 1CaF2 3Ca(PO4)2 +4H2SO4 2H3PO4 +2HF+4CaSO4 H2O

Ch3.1 – Percent Composition and Formulas

Ex1) Find the percentage by mass of ethanol, C2H5OH

Ex2) Find the percentage by mass of carvone, C10H14O

Empirical Formulas

Ex3) Find the empirical formula for a compound found to have the following mass percentages:Cl: 71.65%, C: 24.27% H: 4.07%The molar mass is known to be 98.96g/mol, find the molecular formula.

Ex3) Find the empirical formula for a compound found to have the following mass percentages:Cl: 71.65%, C: 24.27% H: 4.07%The molar mass is known to be 98.96g/molAssume 100 g sample

Divide by the smallest

number if not obvious.ClH2C

Find the molar mass of the empirical formula: 49.48 g/molDivide to find the molecular formula: 98.86 / 49.48 = 2

Cl2H4C2

molgH

molHg

molgC

molCg

molgCl

molClg

04.401.1

14.07 : H

021.201.12

124.27 : C

021.245.35

165.71 : Cl

Ex4) Find the empirical formula for a compound found to contain43.64% phosphorous and 56.36% oxygen.

The molar mass is known to be 283.88g/mol

Ch3 HW#1 p124+

63a,65ac,73,75Lab3.1 Prelab HW

Ex4) Find the empirical formula for a compound found to contain43.64% phosphorous and 56.36% oxygen.

The molar mass is known to be 283.88g/molAssume 100 g sample

Divide by the smallest

number if not obvious.1 : 2.5 ratio?

Just double: 2 : 5 ratio P2O5

Find the molar mass of the empirical formula: 141.94 g/molDivide to find the molecular formula: 283.88 / 141.94 = 2

P4O10

Ch3 HW#1 p124+

63a,65ac,73,75Lab3.1 Prelab HW

molgO

molOg

molgP

molPg

523.300.16

156.36 : O

409.197.30

143.64 : P

Ch3 HW#1 p124+ 63a,65ac,73,75 + Lab3.1 Prelab HW63a. Express the composition of each of the following compounds as the

mass percents of it’s elements.a. formaldehyde, CH2O

63a. Express the composition of each of the following compounds as the

mass percents of it’s elements.a. formaldehyde, CH2O

In 1 mol of formaldehyde :1 mol of C @ 12.0 g/mol = 12.02 mol of H @ 1.0 g/mol = 2.01 mol of O @ 16.00 g/mol = 16.0

30.0 g total

C: 12.0 g H: 2.0 g O: 16.00 g 30.0 g 30.0 g 30.0 g = 40.0% = 6.7% = 53.3%

65. Give the empirical formula for each of the following compounds (for which the common names are given).a. Vitamin C, C6H8O6

c. Acetylene, C2H2

73. Benzene contains only carbon and hydrogen and is 7.74% H by mass; the molar mass of benzene is 78.1 g/mol. Determine the empirical and molecular formulas of benzene.

Assume 100 g sample:

Empirical Formula:

Molecular Formula MassEmpirical Formula Mass

CgCmolg

HgHmolg

0.12 1 C 26.92

0.1 1 H 74.7

73. Benzene contains only carbon and hydrogen and is 7.74% H by mass; the molar mass of benzene is 78.1 g/mol. Determine the empirical and molecular formulas of benzene.

Assume 100 g sample:

1:1

Empirical Formula:

CH

Molecular Formula MassEmpirical Formula Mass

molCgCmolg

molHgHmolg

74.7 0.12 1 C 26.92

74.7 0.1 1 H 74.7

666 00.13

1.78HC

CHgHCg xx

75. Many homes in rural America are heated by propane gas, a compound that contains only carbon and hydrogen. Complete combustion of a sample of propane produced 2.641 g of carbon dioxide and 1.442 g of water as the only products. Find the empirical formula of propane.

1. Chem formula:


1. Chem formula:___CxHy + ___O2 ___CO2 + ___H2O

2. Find the mass of each product:



Given: 2.641g 1.442g2. Find the mass of each product:

1 mol of C @ 12.0 = H2O = 2 mol of O @ 16.0 =




1 mol of C @ 12.0 = 12.0 H2O = 18.0g2 mol of O @ 16.0 = 32.0

44.0g3. Use % to find mass of C and H in each product:




1 mol of C @ 12.0 = 12.0 H2O = 18.0g2 mol of O @ 16.0 = 32.0

44.0g3. Use % to find mass of C and H in each product:

C: 12/44 = 27% H: 2/18 = 11%0.27 x 2.641g = 0.713g 0.11 x 1.442g =

0.160g4. Those masses add up to the mass of the original propane:




CO2 = 44.0g H2O = 18.0g3. Use % to find mass of C and H in each product:

C: 12/44 = 27% H: 2/18 = 11%0.27 x 2.641g = 0.713g 0.11 x 1.442g =

0.160g4. Those masses add up to the mass of the original propane:

0.713g + 0.160g = 0.873g5. Find % of each:

2.7H : 1C2 2/3 H : 1 C 8 : 3 ratio

C3H8

H 160.0 0.1 1 H 160.0

C 0594.0 0.12 1 C 713.0

molHgHmolg

molCgCmolg

Lab3.1 – Empirical Formula Determination Pre-lab Questions1. Read the lab completely. This ensures an efficient and safe experiment.2. Based on your expertise in formula writing, what is your prediction

for the formula for magnesium oxide?3. The manual from which this experiment was reproduced requires a lid

over the crucible, which makes it harder to see the reaction, in fact it slows the reaction so much that the magnesium rarely glows bright. Why do you think this happens?

4. Without a lid, the reaction sometimes occurs so fast, it ‘spatters’ out of the crucible. What effect do you think this would have

on your final mass of magnesium oxide?5. Your teacher may come to your station and put forceps on the Mg

to press it down against the bottom of the crucible. If any reaction has occurred, some grayish/white residue may accompany his forceps out of the crucible. What effect will this have on the final mass of the magnesium oxide?

6. If your mass of magnesium oxide produced comes out lower than expected, what effect will this have on the mole ratio between Mg and O?

Ch3.2 – Limiting Reactants

Ex1) 25.0 g of nitrogen are place in a vessel with 2.0 g of hydrogen. which is the limiting reactant and how much ammonia is produced?

Ch3 HW#2 p127 97 + Equations Rev WS

Lab3.1 Empirical Formulas

- due 2 days

- Ch3 HW#3 % Comp and Empirical Formulas Review HW tonite!

Ch3 HW#3 % Comp and Empirical Formulas Review HW1. Calculate the percent composition of hydrogen cyanide, HCN.

Ch3 HW#3 % Comp and Empirical Formulas Review HW2. Which of the following molecular formulas are also empirical formulas?

a. ribose, C5H10O5, sugar molecule in RNAb. ethyl brutanoate, C6H12O2, a compound with the odor of a pineapplec. chlorophyll, C55H72MgN4O5, part of photosynthesisd. DEET, C12H17ON, an insect repellente. Oxalic acid, H2C2O4, found in spinach and tea

Ch3 HW#3 % Comp and Empirical Formulas Review HW3. Calculate the empirical formula of each compound w/ following % composition.

a. 94.1% O, 5.9% Hb. 79.9% C, 20.1% Hc. 67.6% Hg, 10.8% S, 21.6% Od. 27.59% C, 1.15% H 16.09% N, 55.17% Oe. 17.6% Na, 39.7% Cr, 42.7 O

Ch3 HW#2 p127 97 + Rev WS97. Consider the reaction Mg(s) + I2(s) MgI2(s)

Identify the limiting reagent in each of the reaction mixtures below: a. 100 atoms of Mg and 100 molecules of I2

b. 150 atoms of Mg and 100 molecules of I2

97. Consider the reaction Mg(s) + I2(s) MgI2(s)

1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: a. 100 atoms of Mg and 100 molecules of I2

atoms are directly related to moles (6.02x1023)Neither

b. 150 atoms of Mg and 100 molecules of I2

Iodine


1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: c. 200 atoms of Mg and 300 molecules of I2

d. 0.16 mol Mg and 0.25 mol I2


1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: c. 200 atoms of Mg and 300 molecules of I2

Mg

d. 0.16 mol Mg and 0.25 mol I2

Mg


1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: e. 0.14 mol Mg and 0.14 mol I2

f. 0.12 mol Mg and 0.08 mol I2

g. 6.078 g Mg and 63.46 g I2


1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: e. 0.14 mol Mg and 0.14 mol I2

Equal

f. 0.12 mol Mg and 0.08 mol I2

Iodine

g. 6.078 g Mg and 63.46 g I2

Equal22

22 I 250.0I 253.8

I 1 I 46.63

Mg 0250.0Mg 24.3 Mg 1 Mg 078.6

molg

molg

molg

molg


1mol 1mol 1molIdentify the limiting reagent in each of the reaction mixtures below: h. 1.00 g Mg and 2.00 g I2

i. 1.00 g Mg and 200.00 g I2

Rewrite these word equations as balanced chemical equations.1. carbon + oxygen carbon monoxide

2. potassium nitrate potassium nitrite + oxygen

3. hydrogen + sulfur hydrogen sulfide

4. iron (III) chloride + calcium hydroxide iron (III) hydroxide + calcium chloride

5. sodium + water sodium hydroxide + hydrogen

Ch3.3B – More Limiting ReactantsHW#98) Consider the reaction 2H2(g)+ O2(g) 2H2O(g)Identify the limiting reagent in each of the reaction mixtures given belowa. 50 molecules of H2 and 25 molecules of O2

b. 100 molecules of H2 and 40 molecules of O2

c. 100 molecules of H2 and 100 molecules of O2

d.0.50 mol H2 and .75 mol O2

e. 0.80 mol H2 and .75 mol O2

f. 1.0 g H2 and .50 mol O2

g. 1.00 g H2 and 56.00 g O2

Ch3 HW#4 p127 98,100,102 + Lab3.2 Pre-lab HW

98. Consider the reaction 2H2 (g)+ O2(g) 2H2O(g) 2mol 1mol 2mol

Identify the limiting reagent in each of the reaction mixtures given belowe. 0.80 mol H2 and .75 mol O2

f. 1.0 g H2 and .50 mol O2

g. 1.00 g H2 and 56.00 g O2

Ch3 HW#4 p127 98,100,102 + Lab3.2 Pre-lab HW100. Mercury and Bromine will react with each other to produce

mercury(2) bromide Hg(l) + Br2(l) HgBr2(s) 10.0 g 9.00 g

a. What mass of HgBr2 can be produced from the reaction of 10.0 g Hg and 9.00 g Br2? What mass of which reagent is left unreacted?

100. Mercury and Bromine will react with each other to produce mercury(2) bromide

Hg(l) + Br2(l) HgBr2(s) 10.0 g 9.00 g

a. What mass of HgBr2 can be produced from the reaction of 10.0 g Hg and 9.00 g Br2? What mass of which reagent is left unreacted?

Hg is L.R.

22

22 Br 0563.0 Br 159.8

Br 1 Br 00.9

Hg 0499.0Hg 200.6

Hg 1 Hg 0.10

molg

molg

molg

molg

22

22 HgBr 0.18HgBr 1mol Hg 1mo Hg 200.6 HgBr 360.4g HgBr 1mol Hg 1 Hg 0.10

gg

molg

22

22 Br 02.1 Br 1

Br 159.8 Br 0064.0g

molgmol

100. Mercury and Bromine will react with each other to produce mercury(2) bromide

Hg(l) + Br2(l) HgBr2(s) 5ml 5ml

b. What mass of HgBr2 can be produced from the reaction of 5.00 mL mercury (density = 13.6 g/ml) and 5.00 mL bromine (density = 3.10 g/ml)?

102. Hydrogen cyanide is produced industrially from the reaction of gaseous ammonia, oxygen, and methane.

2NH3(g) + 3O2(g) + 2 CH4(g) 2HCN(g) + 6H2O

If 5.00x103 kg each of NH3, O2, and CH4 are reacted what mass of HCN and of H2O will be produced, assume 100% yield.

Lab3.2 Pre-lab HW1. Steps 3–6 require you to heat your carbonate prior to dissolving it

in distilled water. What is the purpose of this step?

2. Which substance do you think is the limiting reactant in this experiment, the unknown carbonate or the calcium chloride. Justify your answer.

Ch3.3 – Percent YieldEx1) Methanol, CH3OH, is produced from the reaction of hydrogen with

carbon monoxide. If 68.5kg of CO reacts with 8.60kg H2, what is the theoretical yield of methanol? If the actual yield is 35.7kg, what is the percent yield?

HW#104) A student prepared aspirin in a laboratory experiment using a reaction in Exercise 96. C7H6O3 + C4H6O3 C9H8O4 + HC2H3O2

The student reacted 1.50g salicylic acid with 2.00 g acetic anhydride. The yield was 1.50g aspirin. Calculate the theoretical yield and the percent yield for this experiment.

Ch3 HW#5 p128+ 104,105,122

Ch3 HW#7 p128+ 104,105,122105. Aluminum burns in bromine, producing aluminum bromide: 2Al(s) + 3Br2(l) → 2AlBr3(s)

In certain experiments, 6.0g aluminum was reacted with an excess of bromine to yield 50.3g aluminum bromide. Calculate the theoretical and percent yields for this experiment.

Theoretical Yield:

Percent Yield:

122. Nitric acid is produced commercially by the Ostwald process, represented by the following equations:

4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) ? g2NO(g) + O2(g) → 2NO2(g)

3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g) 1.0x106 kg

What mass of NH3 must be used to produce 1.0x106 kg HNO3 by the Ostwald process, assuming 100% yield in each reaction?4:4 ratio 2:2 ratio 3:2 ratio

33

9NH

HNO 100.1

ggx

Ch1 – 3 Rev pg75 50,73a-e,74a-d, pg124 51,53, pg 125 83 Quiz tomorrow! Ch1,2

50. What is the symbol for an ion that has 16 protons, 16 neutrons, and 18 electrons?

73.Write the formula for each of the following compounds: a. sodium oxide

b. sodium peroxide

c. potassium cyanide

d. copper(II) nitrate

e. silicone tetrachloride

74. Write the formula for each of the following compounds: a. ammonium hydrogen phosphate

b. mercury(I) sulfide

c. silicon dioxide

d. sodium sulfite

51. Determine the mass in grams of the following: a. 3.00 x 1020 N2 molecules

b. 3.00 x 10-3 mol N2

c. 1.5 x 102 mol N2

d. A single N2 molecule

e. 2.00 x 10-15 mol N2

f. 18.0 picomoles of N2

g. 5.0 nanomoles of N2

53. Aspartame is an artificial sweetener that is 160 times sweeter than sucrose (table sugar) when dissolved in water. The molecular formula of aspartame is C14H18N2O5.

a. Calculate the molar mass of aspartame.

b. How many moles of molecules are present in 10.0 g aspartame?

c. Calculate the mass in grams of 1.56 mol aspartame.

53. Aspartame is an artificial sweetener that is 160 times sweeter than sucrose (table sugar) when dissolved in water. The molecular formula of aspartame is C14H18N2O5.

d. How many molecules are in 5.0 mg aspartame?

e. How many atoms of nitrogen are in 1.2 g aspartame?

f. What is the mass in grams of 1.0 x 109 molecules of aspartame?

g. What is the mass in grams of one molecule of aspartame?

83. Balance the following equations representing combustion reactions:

a. C12H22O11(s) + O2(g) CO2(g) + H2O(g)

b. C6H6(l) + O2(g) CO2(g) + H2O(g)

c. Fe(s) + O2(g) Fe2O3(s)

d. C4H10(g) + O2 CO2(g) + H2O(g)

e. FeO(s) + O2(g) Fe2O3(s)

Ch1 – 3 Rev #2 pg124 57,67,90 + Ch1,2 Quiz57. In 1987 the first substance to act as a superconductor at a temperature

above that of liquid nitrogen (77 K) was discovered. The approximate formula of this substance is YBa2Cu3O7. Calculate the percent composition by mass of this material.

67. One of the most commonly used white pigments in paint is a compound of titanium and oxygen that contains 59.9% Ti by mass. Determine the empirical formula of this compound.

90. Over the years, the thermite reaction has been used for welding railroad rails, in incendiary bombs, and to ignite solid-feul rocket motors. The reaction is FeO3(s) + 2Al(s) 2Fe(l) + Al2O3(s)What masses of iron(III) oxide and aluminum must be used to produce

15.0 g iron? What is the maximum mass of aluminum oxide that could be produced?

Ch1 – 3 Rev Day 2 Ch1 p37 87,89, Ch2 p77 #86,87, Ch3 pg129 #13087. Confronted with the box shown in the diagram, you wish to discover something about its internal workings. You have no tools and cannot open the box. You pull on the rope B, and it moves rather freely. When you pull on rope A, rope C appears to be pulled slightly into the box. When you pull on rope C, rope A almost disappears into the box.a) Based on these observations, construct a model for the interior mechanism

of the box.b) What further experiments could you do to refine your model?

89) A cylindrical bar of gold that is 1.5in high and 0.25in in diameter has a mass of 23.1984g, as determined on an analytical balance. An empty graduated cylinder is weighed on a triple beam balance and has a mass of 73.47g. After pouring a small amount of liquid into the graduated cylinder, the mass is 79.16g. When the gold cylinder is placed in the graduated cylinder (the liquid covers the top of the gold cylinder), the volume indicated on the graduated cylinder is 8.5mL. Assume that the temperature of the gold bar and the liquid are 86oF. If the density of the liquid decreases by 1.0% for each 10oC rise in temperature (over the range 0 to 50o C) determinea. the density of the gold at 86o F.b. the density of the liquid at 40o F.

Ch2 p77 #86) The early alchemists used to do an experiment in which water was boiled for several days in a sealed glass container. Eventually, some solid residue would appear in the bottom of the flask, which was interpreted to mean that some of the water in the flask had been converted into “earth.” When Lavoisier repeated this experiment, he found that the water weighed the same before and after heating and the mass of the flask plus the solid residue equaled the original mass of the flask. Were the alchemists correct? Explain what really happened.

87) Each of the statements given below is true, but Dalton might have had trouble explaining some of them with his atomic theory. Give explanations for the following statements.

a.) Ethyl alcohol and dimethyl ether have the same composition by mass (52% carbon, 13% hydrogen, and 35% oxygen), yet the two have different melting points, boiling points, and solubilities in water.

b.) Burning wood leaves an ash that is only a small fraction of the mass of the original wood.

c.) Atoms can be broken down into smaller particles.d.) One sample of lithium hydride is 87.4% lithium by mass, while

another sample of lithium hydride is 74.9% lithium by mass. However, the two samples have the same properties.

pg129 #130) From the information below, determine the mass of substance C that will be formed if 45.0g of substance A reacts with 23.0g of substance B. (Assume that the reaction between A and B goes to completion.)

a.) Substance A is a gray solid that consists of an alkaline earth metal and carbon (37.5% by mass). It reacts with substance B to produce substances C and D. Forty million trillion formula units of A have a mass of 4.26mg.

b.)47.9g of substance B contains 5.36g of hydrogen and 42.5g of oxygen.c.) When 10.0g of C is burned in excess oxygen, 33.8g of carbon dioxide and

6.92g of water are produced. A mass spectrum of substance C shows a parent molecular ion with a mass-to-charge ratio of 26.

d.)Substance D is the hydrogen of the metal in substance A.

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AP® CHEMISTRY EQUATIONS AND CONSTANTS Throughout the exam the following symbols have the definitions specified unless otherwise noted. L, mL = liter(s), milliliter(s) mm Hg = millimeters of mercury g = gram(s) J, kJ = joule(s), kilojoule(s) nm = nanometer(s) V = volt(s) atm = atmosphere(s) mol = mole(s) ATOMIC STRUCTURE E = hν c = λν E = energy ν = frequency λ = wavelength Planck’s constant, h = 6.626 × 10−34 J s Speed of light, c = 2.998 × 108 ms−1 Avogadro’s number = 6.022 × 1023 mol−1 Electron charge, e = −1.602 × 10−19 coulomb EQUILIBRIUM Kc = [C] [D] [A] [B] c d a b , where a A + b B R c C + d D Kp = C D A B ( )( ) ( )( ) c d a b P P P P Ka = [H ][A ] [HA] Kb = [OH ][HB ] [B] Kw = [H+][OH−] = 1.0 × 10−14 at 25°C = Ka × Kb pH = −log[H+] , pOH = −log[OH−] 14 = pH + pOH pH = pKa + log [A ] [HA] pKa = −logKa , pKb = −logKb Equilibrium Constants Kc (molar concentrations) Kp (gas pressures) Ka (weak acid) Kb (weak base) Kw (water) KINETICS ln[A]t − ln[A] 0 = − kt > @ > @ A A 0 1 1 t = kt t½ = 0.693 k k = rate constant t = time t ½ = half-life -4- GASES, LIQUIDS, AND SOLUTIONS PV = nRT PA = Ptotal × XA, where XA = moles A total moles Ptotal = PA + PB + PC + . . . n = m M K = °C + 273 D = m V KE per molecule = 1 2 mv 2 Molarity, M = moles of solute per liter of solution A = abc P = pressure V = volume T = temperature n = number of moles m = mass M = molar mass D = density KE = kinetic energy v = velocity A = absorbance a = molar absorptivity b = path length c = concentration Gas constant, R = 8.314 J mol−1K−1 = 0.08206 L atm mol−1 K−1 = 62.36 L torr mol−1 K−1 1 atm = 760 mm Hg = 760 torr STP = 273.15 K and 1.0 atm Ideal gas at STP = 22.4 L molí1 THERMODYNAMICS / ELECTROCHEMISTRY q = mc∆T ∆S° = Ç Ç S S D D products reactants ∆H° = products reactants H H f f Ç Ç D D D D ∆G° = products reactants G G f f Ç Ç D D D D ∆G° = ∆H° − T∆S° = −RT ln K = − n E° I = q t q = heat m = mass c = specific heat capacity T = temperature S° = standard entropy H° = standard enthalpy G° = standard Gibbs free energy n = number of moles E° = standard reduction potential I = current (amperes) q = charge (coulombs) t = time (seconds) Faraday’s constant, = 96,485 coulombs per mole of electrons 1 volt = 1 joule 1 coulomb

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Day 1: 1. Hand out syllabus and lab1.1 2. Syllabus - homework policy 3. Lab safety

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