Problems & Step-by-Step Video Solutions
Catalog of solved problems on videos. Topics include: stoichiometry, reactions in solutions, gas laws, atomic structure, bonding, kinetics, equilibrium, acid-base, thermodynamics, electrochemsitry and many more. Select MyBookTM to automatically search for solutions and tutorials in our video archive that are similar to the problems in your book. Then click on a question # to see problem and solution.
Ch. | Sec. | ||||
01 | Chemistry Basics | ||||
01 | Measurments, uncertainty and errors | ||||
#Tutorial 19 Video Runtime: 07:28 Solution: PC|Mac :: Android|iOS | This lesson discusses unit conversions and the method of dimensional analysis. | ||||
#Tutorial 20 Video Runtime: 05:03 Solution: PC|Mac :: Android|iOS | This lesson discusses what the uncertainty of a measurement means and how to describe the statistical and systematic errors of a measurement. | ||||
02 | Atoms, Molecules, Ions | ||||
02 | Laws of definite proportion and multiple proportions | ||||
#02-02-00 Video Runtime: 03:01 Solution: PC|Mac :: Android|iOS | A certain element X and oxygen form four different binary compounds. These compounds have the following compositions:
(a) Show that the law of multiple proportions holds for these compounds. (b) If the molecular formula for compound A is X2O, what are the molecular formulas for compounds B, C and D? |
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05 | Structure of the atom | ||||
#02-05-00 Video Runtime: 02:51 Solution: PC|Mac :: Android|iOS | Chlorine has two prevalent isotopes Cl-35 and Cl-37. Determine the number of protons, neutrons and electrons in each and write down its full atomic symbol. | ||||
06 | Molecules and ions | ||||
#Tutorial 04 Video Runtime: 05:24 Solution: PC|Mac :: Android|iOS | This lesson discusses the role of the electron in chemical reactions when atoms or molecules form ions. | ||||
#Tutorial 05 Video Runtime: 04:21 Solution: PC|Mac :: Android|iOS | In this lesson, we will give you some general rules to help determine whether two atoms are likely to form a bond. | ||||
#02-06-00 Video Runtime: 02:35 Solution: PC|Mac :: Android|iOS | (a) When they form ionic compounds, which elements in the 3rd row of the periodic table are expected to lose electrons? Which ones should gain electrons? (b) If the following binary compounds are formed from elements in the 3rd row of the periodic table, determine whether that compound should be ionic or covalent: S with Cl, Mg with S, Al with P. |
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08 | Naming compounds | ||||
#02-08-00 Video Runtime: 04:19 Solution: PC|Mac :: Android|iOS | (a) Provide systematic names of the following compounds: AlCl3 , FeSO3, N2O5. (b) Provide formula for the following compounds:cesium hydrogen carbonate, copper (I) sulfate, mercury (I) chloride. |
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03 | Stoichiometry | ||||
01 | Atomic theory and stoichiometry | ||||
#Tutorial 01 Video Runtime: 03:31 Solution: PC|Mac :: Android|iOS | The concept of atoms is central to all of chemistry. A proper understanding of atoms is particularly key to mastering stoichiometry. In this lesson, we will look at the implications of atoms on stoichiometry in a different way. | ||||
03 | Molar mass | ||||
#03-03-00 Video Runtime: 03:55 Solution: PC|Mac :: Android|iOS | (a) Calculate the molar mass of calcium phosphate, Ca3(PO4)2. (b) Calculate the mass of Ca, P and O in 100.0 g of calcium phosphate and the number of atoms of each. |
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04 | Mass composition of compoundss | ||||
#03-04-00 Video Runtime: 03:05 Solution: PC|Mac :: Android|iOS | Calculate the mass percentages of Al, S and O in aluminum sulfate. | ||||
05 | Empirical formula | ||||
#03-05-00 Video Runtime: 04:54 Solution: PC|Mac :: Android|iOS | (a) A certain compound has the following mass composition: 5.15% hydrogen, 49.48% carbon, 28.87% nitrogen and 16.49% oxygen. Determine its empirical formula. (b) This compound has a molar mass of approximately 195 g/mol. What is its molecular formula? |
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07 | Balancing chemical equations | ||||
#03-07-00 Video Runtime: 05:04 Solution: PC|Mac :: Android|iOS | Balance the following reactions: (a) NH3 + O2 → NO + H2O (b) The compound C8H10N4O2 is burned in oxygen to produce CO2, H2O and N2. (c) An acidic solution of dichromate ions reacts with metallic aluminum to form chromium (III) oxide, aluminum ions and water. |
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08 | Stoichiometry calculations | ||||
#Tutorial 02 Video Runtime: 05:22 Solution: PC|Mac :: Android|iOS | This lesson will explain the basic concept of what a limiting reagent is and its role in a stoichiometry calculation. | ||||
#Tutorial 03 Video Runtime: 03:04 Solution: PC|Mac :: Android|iOS | This lesson explains how to determine the number of moles for a stoichiometry calculation if the reaction involves solids, liquids, solutions or gases. | ||||
#03-08-00 Video Runtime: 03:07 Solution: PC|Mac :: Android|iOS | Metallic lead can be produced from lead (IV) oxide according to the following reaction: PbO2(s) + 2CO(g) → Pb(s) + 2CO2(g) What is the mass of lead (IV) oxide required to produced 1000. kg of Pb? How many kg of CO2 gas is produced in this process? |
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#03-08-01 Video Runtime: 06:36 Solution: PC|Mac :: Android|iOS | Mn2O3 reacts with S to form MnO and SO2. If 5.674 g of Mn2O3 is reacted with 0.835 g of S, which one is the limiting reagent? What mass of MnO and SO2 is produced? | ||||
#03-08-02 Video Runtime: 04:29 Solution: PC|Mac :: Android|iOS | For the following reaction: Fe(s) + 2 Cr(s) + 4 CO(g) → FeCr2O4(s) + 4 C(s) if 10.00 g of each of Fe, Cr and CO are reacted with each other, what is the theoretical yield of FeCr2O4 by mass? |
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04 | Solution Stoichiometry | ||||
03 | Concentrations | ||||
#Tutorial 03 Video Runtime: 03:04 Solution: PC|Mac :: Android|iOS | This lesson explains how to determine the number of moles for a stoichiometry calculation if the reaction involves solids, liquids, solutions or gases. | ||||
#04-03-00 Video Runtime: 01:04 Solution: PC|Mac :: Android|iOS | A 0.235 M solution of NaCl is to be produced by diluting a 1.87 M NaCl stock solution. What is the volume of 1.87 M NaCl needed to produce 573. mL of 0.235 M NaCl? | ||||
#04-03-01 Video Runtime: 03:01 Solution: PC|Mac :: Android|iOS | Calculate the final chloride ion concentration in the following: (a) 25.64 mL of 1.35 M calcium chloride diluted to a final volume of 214.0 mL. (b) 125. mL of 0.562 M calcium chloride is mixed with 75.0 mL of 0.825 M NaCl. |
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04 | Common reactions in solutions | ||||
#Tutorial 11 Video Runtime: 03:38 Solution: PC|Mac :: Android|iOS | This lesson discusses the most common types of reactions occurring in solutions. | ||||
05 | Precipitation reactions | ||||
#04-05-00 Video Runtime: 06:30 Solution: PC|Mac :: Android|iOS | 68.5 mL of 0.430 M potassium sulfate is mixed with 56.3 mL of 0.550 M barium nitrate. (a) What is the precipitate? (b) Write down the net ionic equation. (c) Calculate the mass of the precipitate produced? (d) Calculate the concentration of all ions in the final solution. |
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08 | Acid-base reactions | ||||
#04-08-00 Video Runtime: 02:02 Solution: PC|Mac :: Android|iOS | 52.45 mL of a sulfuric acid solution with an unknown concentration is titrated with 0.4325 M NaOH. 123.85 mL of NaOH is needed to reach the endpoint. Calculate the original concentration of the sulfuric acid solution. | ||||
09 | Oxidation-reduction reactions | ||||
#04-09-00 Video Runtime: 02:59 Solution: PC|Mac :: Android|iOS | (a) Determine the oxidation state of all elements in the following (unbalanced) reaction: HNO3(aq) + Fe(s) → NO(g) + FeNO3(aq) (b) Which reactant is the oxidizing agent? Which one is the reducing agent? |
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10 | Balancing redox equations | ||||
#Tutorial 06 Video Runtime: 04:29 Solution: PC|Mac :: Android|iOS | This lesson explains how to use the half-reaction method to balance any redox equation. | ||||
#04-10-00 Video Runtime: 02:42 Solution: PC|Mac :: Android|iOS | Balance the following redox equation: Co3+ + Hg → Co2+ + Hg22+ |
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#04-10-01 Video Runtime: 03:33 Solution: PC|Mac :: Android|iOS | (a) Balance the following redox equation in acidic solution: Cu + HNO3 (aq) → Cu2+ (aq) + NO (g) |
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#04-10-02 Video Runtime: 06:25 Solution: PC|Mac :: Android|iOS | (a) Balance the following redox equation in acidic solution: C2H5OH (aq) + MnO4- (aq) → MnO2 (s) + CO2 (g) (b) Balance the same reaction in basic solution. |
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05 | Gases and Reactions Involving Gases | ||||
01 | Pressure | ||||
#05-01-00 Video Runtime: 01:26 Solution: PC|Mac :: Android|iOS | At room temperature, the vapor pressure of water is approximately 25 torr. Convert this to atm and psi. | ||||
02 | Gas laws | ||||
#05-02-00 Video Runtime: 02:47 Solution: PC|Mac :: Android|iOS | A gas starts at 742. torr and 25.0 oC with an initial volume of 3.27 L. (a) It is first heated to 65.5 oC at constant pressure. Calculate its new volume. (b) The gas is then compressed at constant temperature back to 1.85 L. Calculate its new pressure. |
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04 | The ideal gas law | ||||
#05-04-00 Video Runtime: 02:35 Solution: PC|Mac :: Android|iOS | Calculate the density of air at STP. | ||||
#05-04-01 Video Runtime: 02:07 Solution: PC|Mac :: Android|iOS | At high temperature, solid ammonium hydroxide (NH4OH) decomposes to water vapor and NH3 gas. 12.6 g of ammonium hydroxide is placed in an evacuated 1L-flask and then heated to 250. oC. The ammonium hydroxide is allowed to decompose completely. Determine the final pressure of the gas mixture inside the flask. | ||||
#05-04-02 Video Runtime: 04:32 Solution: PC|Mac :: Android|iOS | Propene gas (C3H6) burns in oxygen gas to form carbon dioxide and water vapor. A sample of propene gas having a volume of 2.35 L at 25 oC and 1.50 atm is mixed with 6.45 L of O2 gas at 45 oC and 2.00 atm and the mixture is ignited. Determine the mass of carbon dioxide produced. | ||||
05 | Partial pressures | ||||
#05-05-00 Video Runtime: 02:38 Solution: PC|Mac :: Android|iOS | The reaction between nitrogen gas and hydrogen gas makes NH3 gas. A mixture of N2 and H2, each with a partial pressure of 0.500 atm is reacted to completion at a constant temperature of 635 K inside a fixed-size vessel. Determine the total pressure of the product. | ||||
06 | Kinetic theory of gases | ||||
#05-06-00 Video Runtime: 03:41 Solution: PC|Mac :: Android|iOS | (a) Calculate the root mean square velocities of O2 and H2 gas at room temperature. (b) An equimolar mixture of O2 and H gas are held in a Knudson cell and allowed to effuse through a small pinhole. Which gas escapes faster? What are their relative rates of effusion? |
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06 | Thermochemistry and the First Law of Thermodynamics | ||||
01 | Energy, heat and work | ||||
#Tutorial 10 Video Runtime: 06:23 Solution: PC|Mac :: Android|iOS | This lesson explains the basic concepts of thermochemistry and the 1st Law of Thermodynamics. | ||||
#06-01-00 Video Runtime: 02:30 Solution: PC|Mac :: Android|iOS | 586. J of energy is used to heat a gas from 298. K to 345. K. The gas expands from 5.64 L to 13.50 L against an external pressure of 1.00 atm. Calculate the total change in internal energy of the gas. | ||||
02 | Enthalpy and calorimetry | ||||
#06-02-00 Video Runtime: 01:51 Solution: PC|Mac :: Android|iOS | Calculate the final temperature when a 40.0 g sample of aluminum (specific heat capacity 0.890 J/K/g) at 65.0 oC is dropped into 100. g of water (specific heat capacity 4.18 J/K/g) at 20.0 oC. | ||||
#06-02-01 Video Runtime: 03:08 Solution: PC|Mac :: Android|iOS | When a 4.25-g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter, the temperature decreases from 22.06 oC to 16.9 oC. Calculate DH (in kJ/mol NH4OH) for the solution process: NH4OH (s) → NH4+ (aq) + OH- (aq) Assume that the specific heat capacity of the solution is 4.22 J/g/K. |
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03 | Hess's law | ||||
#06-03-00 Video Runtime: 02:17 Solution: PC|Mac :: Android|iOS | Given the following data: N2 (g) + O2 (g) → 2 NO (g) DH = +180.7 kJ 2 NO (g) + O2 (g) → 2 NO2 (g) DH = -113.1 kJ 2 N2O (g) → 2 N2 (g) + O2 (g) DH = -163.2 kJ calculate DH for the reaction: NO2 (g) + N2O (g) → 3 NO (g) |
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04 | Enthalpy of reactions | ||||
#06-04-00 Video Runtime: 02:02 Solution: PC|Mac :: Android|iOS | Solid glucose (C6H12O6) burns in oxygen gas (O2) to form CO2 gas and water vapor. Use standard enthalpies of formation to calculate the standard molar enthalpy change of this reaction. | ||||
07 | Electronic Structure of the Atom | ||||
02 | Light and waves | ||||
#07-02-00 Video Runtime: 01:28 Solution: PC|Mac :: Android|iOS | Lasers can be made with different materials. (a) CO2 lasers produce light with a 10.6 micron wavelength. What is the frequency of this light? Is it in the visible, IR, or UV? (b) An Argon ion laser produces light with a 514 nm wavelength. What is its frequency? Is it in the visible, IR or UV? |
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03 | Wave nature of matter | ||||
#07-03-00 Video Runtime: 01:37 Solution: PC|Mac :: Android|iOS | What is the de Broglie wavelength of an electron traveling at 1% the speed of light? |
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04 | The hydrogen atom and electron energy levels | ||||
#07-04-00 Video Runtime: 03:12 Solution: PC|Mac :: Android|iOS | In an excited hydrogen atom, an electron falls from the 6f orbital to the 2p orbital. Calculate the wavelength of the resulting emission. | ||||
06 | One-electron atoms | ||||
#07-06-00 Video Runtime: 01:25 Solution: PC|Mac :: Android|iOS | Is the following set of quantum numbers allowed: n=3, l=2, ml=2? | ||||
#07-06-01 Video Runtime: 01:51 Solution: PC|Mac :: Android|iOS | How many different orbitals are there in the n=8 shell? | ||||
08 | Many-electron atoms | ||||
#07-08-00 Video Runtime: 01:40 Solution: PC|Mac :: Android|iOS | What is the electronic configuration of Cu? | ||||
#07-08-01 Video Runtime: 01:47 Solution: PC|Mac :: Android|iOS | What is the electronic configuration of Ir? | ||||
#07-08-02 Video Runtime: 01:58 Solution: PC|Mac :: Android|iOS | Predict the electronic configuration of the as yet undiscovered element with atomic number 116. | ||||
09 | Periodic trends | ||||
#07-09-00 Video Runtime: 02:20 Solution: PC|Mac :: Android|iOS | Of the atoms P, S, Ar, Se, Sb and Sn: (a) which one has the smallest size? (b) which one has the lowest ionization energy? (c) which one has the highest electron affinity? |
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08 | Bonding, Lewis Structures and VSEPR | ||||
01 | Ionic bonds | ||||
#08-01-00 Video Runtime: 01:09 Solution: PC|Mac :: Android|iOS | MgO has about the same bond distance as NaF. Which compound forms a stronger bond? | ||||
02 | Electronic configurations of ions | ||||
#08-02-00 Video Runtime: 01:24 Solution: PC|Mac :: Android|iOS | What is the electronic configuration of: Sr2+, Fe2+ and Fe3+? | ||||
03 | Covalent bonds and bond polarity | ||||
#08-03-00 Video Runtime: 02:36 Solution: PC|Mac :: Android|iOS | Which of the following molecules is expected to have the highest bond polarity: N2, CO, KF, ICl? | ||||
08 | Covalent bond energies | ||||
#08-08-00 Video Runtime: 02:30 Solution: PC|Mac :: Android|iOS | Acetylene (C2H2) is a gas often used in welding. Use average bond enthalpies to estimate the heat delivered when 1 mole of acetylene is burned in air. (The C-C bond in acetylene is a triple bond.) | ||||
10 | Lewis structures | ||||
#Tutorial 08 Video Runtime: 04:11 Solution: PC|Mac :: Android|iOS | This lesson shows you how to easily determine the Lewis structure of a molecule. | ||||
#Tutorial 09 Video Runtime: 05:24 Solution: PC|Mac :: Android|iOS | This lesson shows you how to determine the Lewis structure of a molecule and use it to assign formal charges to all atoms in the molecule. | ||||
#08-10-00 Video Runtime: 15:01 Solution: PC|Mac :: Android|iOS | Draw Lewis structures and assign formal charges for the following molecules: PH3, CH2O, POCl3, SF2. | ||||
#08-10-01 Video Runtime: 13:44 Solution: PC|Mac :: Android|iOS | Draw Lewis structures and assign formal charges for the following molecules: ClO2-, NO2-, SF4. | ||||
11 | Exceptions to the octet rule | ||||
#08-11-00 Video Runtime: 06:34 Solution: PC|Mac :: Android|iOS | Which of the following violate(s) the octet rule: O3, PCl5, I3-, PO43-, XeF4. | ||||
12 | Resonance structures | ||||
#08-12-00 Video Runtime: 08:09 Solution: PC|Mac :: Android|iOS | In each of the molecules: SO, SO2, SO3, SO32-, all S-O bonds are equivalent. Use resonance structures to determine the bond order of each S-O bond in each molecule. (S is the center atom in all molecules.) | ||||
13 | VSEPR | ||||
#Tutorial 07 Video Runtime: 03:20 Solution: PC|Mac :: Android|iOS | This lesson shows you how to do VSEPR easily, without having to first draw the Lewis structure. This method will work for all molecules where there is one center atom and all the other atoms are bonded to it. | ||||
#08-13-00 Video Runtime: 10:20 Solution: PC|Mac :: Android|iOS | Use VSEPR to determine the geometry of the following molecules: XeF4, SO2, SO3, PF3. (In each molecule, the first atom is the center atom.) | ||||
#08-13-01 Video Runtime: 07:31 Solution: PC|Mac :: Android|iOS | Use VSEPR to determine the geometry of the following molecules: PCl5, I3-,SF6. (In each molecule, the first atom is the center atom.) | ||||
09 | Molecular Orbitals | ||||
01 | Hybridized atomic orbitals | ||||
#09-01-00 Video Runtime: 01:50 Solution: PC|Mac :: Android|iOS | What is the hybridization on the carbon atoms in the following molecules: CH4, C2H6, C2H4, C2H2, CO, CO2, CO32-. | ||||
03 | Molecular orbital theory of diatomic molecules | ||||
#09-03-00 Video Runtime: 03:35 Solution: PC|Mac :: Android|iOS | Draw the MO diagram for the following diatomic molecules: C2, O2 , and N2. For each, determine its bond order and whether the molecule is paramagnetic. | ||||
#09-03-01 Video Runtime: 01:40 Solution: PC|Mac :: Android|iOS | NO is one of the molecules that do not obey the octet rule, and its bonding cannot be fully explained by Lewis structure. But MO theory has no such problem. What is the correct bond order of this molecule? | ||||
12 | Kinetics | ||||
01 | Definition of reaction rates | ||||
#Tutorial 12 Video Runtime: 05:17 Solution: PC|Mac :: Android|iOS | This lesson explains the basic concepts of reaction kinetics and differential and integrated laws of first and second order reactions. | ||||
#12-01-00 Video Runtime: 03:47 Solution: PC|Mac :: Android|iOS | For the reaction: 2 N2O5(g) --> 4 NO2(g) + O2(g) (a) How is the rate of appearance of NO2 (d[NO2]/dt) related to the rate of disappearance of N2O5 and the rate of appearance of O2? (b) If this reaction is second-order in N2O5, write down the rate law. What is the correct unit for the rate constant? |
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03 | Method of intitial rates | ||||
#12-03-00 Video Runtime: 05:04 Solution: PC|Mac :: Android|iOS | For the reaction: A + 2 B + 4 C --> products (a) Use the following initial rate data to determine the rate law.
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04 | Integrated rate laws | ||||
#12-04-00 Video Runtime: 04:43 Solution: PC|Mac :: Android|iOS | For the reaction: B(g) --> products a certain amount of B was placed in a sealed container and allowed to react. (a) The following concentration data were obtained at different times.
What is the order of the reaction in B? (b) What is the value of the rate constant? (c) What is the initial concentration of B at 0s? |
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06 | Reaction mechanicsms | ||||
#Tutorial 13 Video Runtime: 05:23 Solution: PC|Mac :: Android|iOS | This lesson explains how to use reaction mechanisms to derive the overal rate law and discusses the role of reaction intermediates and catalysts in a mechanism. | ||||
#12-06-00 Video Runtime: 03:59 Solution: PC|Mac :: Android|iOS | (a) Write down the overall reaction for the following mechanism: NO2(g) + F2(g) --> NO2F + F (fast equilibrium) F + NO2 --> NO2F (slow) (b) Which species is (are) the intermediates? Is any species acting as a catalyst? (c) Determine the overall rate law. |
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07 | Temperature dependence of rates | ||||
#12-07-00 Video Runtime: 04:18 Solution: PC|Mac :: Android|iOS | (a) A certain chemical reactions is twice as fast at 60 oC compared to 30 oC, calculate the activation energy of this reaction. (b) The reaction is exothermic with a DH = -46 kJ/mol. Sketch the energy profile for this reaction. What is the activation energy for the reverse reaction? |
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13 | Chemical Equilibrium | ||||
01 | The basic concept of equilibrium | ||||
#Tutorial 14 Video Runtime: 06:59 Solution: PC|Mac :: Android|iOS | This lesson discusses the basic ideas of chemical equilibrium and how to set up an ICE calculation. | ||||
03 | Equilibrium expressions involving pressures | ||||
#13-03-00 Video Runtime: 04:07 Solution: PC|Mac :: Android|iOS | (a) Write down the equilibrium expression for the following reaction: 2 N2O5(g) --> 4 NO2(g) + O2(g) (b) If the equilibrium constant Kp for this reaction is 0.00352 at 330 K, what is the value of the equilibrium constant Kc at this temperature? (c) What is the equilibrium constant Kc for the reverse reaction? |
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05 | The reaction quotient and extent of reaction | ||||
#Tutorial 15 Video Runtime: 08:08 Solution: PC|Mac :: Android|iOS | This lesson discusses the reaction quotient and gives you additional tools for handling typical ICE calculations. | ||||
#13-05-00 Video Runtime: 09:26 Solution: PC|Mac :: Android|iOS | For the reaction: H2(g) + F2(g) --> 2HF(g) the equilibrium constant is 12.1. (a) If initially 0.500 mole of H2, 0.300 mole of F2 and 1.000 mole of HF were mixed in a 1.50-L flask, which way will the reaction move to reach equilibrium? (b) Calculate the equilibrium concentrations of all three species. |
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06 | Equilibrium calculations | ||||
#13-06-00 Video Runtime: 04:32 Solution: PC|Mac :: Android|iOS | The equilibrium constant for the reaction: 2 N2O5(g) --> 4 NO2(g) + O2(g) is 1.3 x 10-6. If N2O5 with an initial concentration of 1.000 M is allowed to react to equilibrium, calculate the equilibrium concentrations of all three species. |
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07 | Le Chatelier's principle | ||||
#13-07-00 Video Runtime: 02:15 Solution: PC|Mac :: Android|iOS | For the following reaction: UO2(s) + 4HF(g) <=> UF4(g) + 2H2O(l) DH = +23.2 kJ/mol how will the following changes affect the equilibrium?
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14 | Acid Base Equilibria | ||||
01 | Introduction to acid-base reactions | ||||
#Tutorial 16 Video Runtime: 09:15 Solution: PC|Mac :: Android|iOS | This lesson describes the key to understanding acid base equilibrium, pH and acid and base strengths. | ||||
02 | Acid and base strengths | ||||
#14-02-00 Video Runtime: 02:46 Solution: PC|Mac :: Android|iOS | Using the table of Ka values, order the following bases by their relative strength: H2O, F-, Cl-, NO2- and CN-. |
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03 | pH and pOH | ||||
#14-03-00 Video Runtime: 01:42 Solution: PC|Mac :: Android|iOS | (a) What is the H3O+ and OH- concentration in a pH 4.550 buffer solution? (b) What is the pOH? |
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04 | pH of strong acids | ||||
#14-04-00 Video Runtime: 00:45 Solution: PC|Mac :: Android|iOS | Calculate the pH of a 0.0475 M solution of HCl. | ||||
05 | pH of weak acids | ||||
#14-05-00 Video Runtime: 04:42 Solution: PC|Mac :: Android|iOS | (a) Calculate the pH of a 0.0475 M solution of HNO2. (b) Calculate the percent dissociation. |
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#14-05-01 Video Runtime: 04:33 Solution: PC|Mac :: Android|iOS | (a) Calculate the pH of a solution containing 0.0475 M HNO2 and 0.100 M NH4Cl. (b) Calculate the concentrations of all dissolved species in this solution. |
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#14-05-02 Video Runtime: 03:42 Solution: PC|Mac :: Android|iOS | Calculate the pH of a 1.00 M solution of HCN. | ||||
06 | pH of basic solutions | ||||
#14-06-00 Video Runtime: 04:15 Solution: PC|Mac :: Android|iOS | The Ka of a certain monoprotic acid HX is 3.87 x 10-6. (a) Calculate the Kb of its conjugate base X-. (b) Calculate the pH of a 0.0475 M solution of NaX. |
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07 | Polyprotic acids | ||||
#14-07-00 Video Runtime: 06:40 Solution: PC|Mac :: Android|iOS | Calculate the concentrations of all dissolved species in a 1.00 M solution of oxalic acid. (Oxalic acid is a diprotic acid: Ka1 = 6.5x10-2, Ka2 = 6.1x10-5.) |
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08 | Acid-base properties of salts | ||||
#14-08-00 Video Runtime: 04:34 Solution: PC|Mac :: Android|iOS | Determine whether the following will produce an acidic, basic or neutral solutions when dissolved in water: KNO2, NaCH3COO, K2O, NaCl, NH4Cl,NH4NO2. | ||||
15 | Buffers, Solubility and Complex Ion Equilibria | ||||
02 | Buffers | ||||
#15-02-00 Video Runtime: 06:41 Solution: PC|Mac :: Android|iOS | (a) How much NaOH has to be dissolved in 500. mL of 0.400 M acetic acid to form a pH = 4.500 buffer? (b) If HCl gas is dissolved in this buffer, how will the pH change? (c) How many moles of HCl can be dissolved in this buffer before the pH changes by 0.500? |
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04 | Acid-base titrations | ||||
#15-04-00 Video Runtime: 10:17 Solution: PC|Mac :: Android|iOS | 50.00 mL of a 0.100 M solution of methyl amine (CH3NH2) is titrated with 0.150 M HNO3. (a) Calculate the volume of HNO3 needed to reach the equivalence point. (b) Calculate the pH at the equivalence point. (c) Calculate the pH after 10.0 mL of HNO3 has been added. (d) Calculate the pH after 50.0 mL of HNO3 has been added. |
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#15-04-01 Video Runtime: 06:32 Solution: PC|Mac :: Android|iOS | 60.0 mL of a weak monoprotic acid of an unknown concentration is titrated with 0.100 M NaOH. 86.3 mL of NaOH is needed to reach the equivalence point. (a) What is the concentration of the weak acid? (b) The pH at the half-equivalence point is 5.87. Calculate the Ka of this unknown acid? (c) From your answers to (a) and (b), calculate the pH at the equivalence point. |
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06 | Solubility equilibria | ||||
#15-06-00 Video Runtime: 06:17 Solution: PC|Mac :: Android|iOS | The Ksp for CaF2 is 4.0 x 10-11. (a) Calculate the solubility of CaF2 in pure water. (b) Calculate the solubility of CaF2 in a 0.100 M KF solution. (c) When 100.0 mL of 0.100 M Ca(NO3)2 is mixed with 100.0 mL of 0.0100 M KF, will a precipitate form? |
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08 | Complex ion equilibria | ||||
#15-08-00 Video Runtime: 03:20 Solution: PC|Mac :: Android|iOS | Calculate the concentrations of Hg2+, I- and of the complex [HgI4]2- in a solution containing 1.00 M mercury (II) nitrate and 1.00 M potassium iodide. The equilibrium constant for the formation of the complex [HgI4]2- is 1.0 x 1030. | ||||
16 | Entropy and the Second Law of Thermodynamics | ||||
04 | Free energy | ||||
#16-04-00 Video Runtime: 07:10 Solution: PC|Mac :: Android|iOS | (a) Calculate the boiling point of methyl alcohol (CH3OH). (b) Calculate the vapor pressure of methyl alcohol at 25 oC. |
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06 | Free energy change in chemical reactions | ||||
#16-06-00 Video Runtime: 10:09 Solution: PC|Mac :: Android|iOS | For the reaction: 2SO2(g) + O2(g) --> 2SO3(g) (a) Calculate DH0, DS0, and DG0 . (b) Explain the sign of DS0. (c) Is this reaction spontaneous at standard condition? (d) Calculate the equilibrium constant of this reaction at 298 K. (e) Calculate the equilibrium constant of this reaction at 1000 K. (f) The following mixture of the three gases are prepared in a 1.000-L flask at 1000 K: 0.300 mole of SO2, 0.200 mole of O2 and 2.50 mole of SO3. In which direction is the reaction spontaneous? |
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08 | Free energy and equilibrium | ||||
#16-08-00 Video Runtime: 07:10 Solution: PC|Mac :: Android|iOS | (a) Calculate the boiling point of methyl alcohol (CH3OH). (b) Calculate the vapor pressure of methyl alcohol at 25 oC. |
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17 | Electrochemistry | ||||
03 | Cell potentials, electrical work and free energy | ||||
#17-03-00 Video Runtime: 07:56 Solution: PC|Mac :: Android|iOS | Consider the following (at standard conditions): Na+, Cl-, Ag+, Ag, Zn2+, Zn, Pb, Fe, Fe2+, Mg, Mg2+, Sn (a) Which ones can act as oxidizing agents? Which one is the strongest oxidizing agent? (b) Out of the list in (a), which species can be reduced by Al? (c) Which ones can act as reducing agents? Which one is the strongest reducing agent? (d) Out of the list in (c), which species can be oxidized by Fe3+? |
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04 | Concentration dependence of cell potentials | ||||
#17-04-00 Video Runtime: 05:58 Solution: PC|Mac :: Android|iOS | A galvanic cell is based on the following redox reaction: Zn + Cu2+ --> products (a) Write down the products of this reaction. (b) Calculate the standard cell potential. (c) Make a sketch of this cell and label all the relevant parts. (d) Calculate the cell potential if everything is at standard condition except for [Cu2+] = 1.00 x 10-4 M. (e) Ammonia forms a complex with Cu2+. How will the addition of ammonia to the copper half-cell affect the cell potential? |
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#17-04-01 Video Runtime: 04:10 Solution: PC|Mac :: Android|iOS | A concentration cell is constructed using two Ag/Ag+ half-cells with the same volume. (a) The concentration of Ag+ in one cell is 1.00 M and 0.100 M in the other. Calculate the cell potential. (b) When the reaction proceeds, what happens to the concentrations in the two half-cells? (c) Which side is the cathode? (d) When will the reaction stop? What is the concentration in each half-cell when the reaction stops, assuming that the two half-cells have the same volume? |
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#17-04-02 Video Runtime: 03:05 Solution: PC|Mac :: Android|iOS | Use the following standard reduction potentials to calculate the Ksp of mercury (I) chloride. Hg2Cl2 + 2e- --> 2Hg + 2Cl- +0.34 V Hg22+ + 2e- --> 2Hg +0.80 V |
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07 | Electrolytic cells | ||||
#17-07-00 Video Runtime: 00:46 Solution: PC|Mac :: Android|iOS | A solution in an electrolytic cell contains Cu2+, Ag+ and Au3+. When a current is applied to the cell, which metal will be plated out first? Second? And last? | ||||
#17-07-01 Video Runtime: 01:03 Solution: PC|Mac :: Android|iOS | An electrolysis is used to plate gold from a Au3+ solution at a constant current of 15 A onto a metal surface. What is the mass of gold plated out in one hour? | ||||
20 | Coordination Chemistry | ||||
03 | Naming coordination compounds | ||||
#20-03-00 Video Runtime: 05:05 Solution: PC|Mac :: Android|iOS | Give systematic names for the following compounds: (a) [Co(NH3)5Cl]Cl2 (b) K3[Fe(CN)6] (c) [Fe(en)2(NO2)2]2SO4 Provide chemical formula for the following: (a) tetracarbonyldifluoroiron (III) nitrate (b) bis(ethylenediamine)diamminecolbalt (III) tetrachloroplatinate (II) |
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04 | Isomerism | ||||
#20-04-00 Video Runtime: 02:22 Solution: PC|Mac :: Android|iOS | Draw all distinct isomers of the following complexes: (a) [Co(en)3]2+ (a) [Co(CO)2(en)2]2+ |
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#20-04-01 Video Runtime: 01:40 Solution: PC|Mac :: Android|iOS | How many coordination isomers does the compound Fe(CO)4BrClI have? (In this compound, Fe is 6-coordinate.) | ||||
06 | Crystal field theory | ||||
#20-06-00 Video Runtime: 03:56 Solution: PC|Mac :: Android|iOS | Explain the following observations by using the crystal field theory and the proper electronic configurations of the d-orbitals in these complexes: (a) Fe(CN)64- is diamagnetic but Fe(H2O)62+ is paramagnetic. (b) Co3+ forms an octahedral complex with an unknown monodentate ligand L. It has an orange color. Is the ground-state complex likely to be paramagnetic or diamagnetic? Why? |
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21 | Nuclear Chemistry | ||||
01 | Radioactive decay | ||||
#21-01-00 Video Runtime: 02:26 Solution: PC|Mac :: Android|iOS | (a) 210Po undergoes an a-particle decay. What nuclide does this produce? (b) The products of a nuclear decay reaction is a b-particle and 131Xe. What is the original nuclide. |
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04 | Radioisotope dating | ||||
#21-04-00 Video Runtime: 01:31 Solution: PC|Mac :: Android|iOS | The 14C:12C ratio in a piece of cloth found in an archeological site has 82.3% its present-day value. Carbon-14 has a half life of 5730 years. Calculate the age of this material. | ||||
05 | Thermodynamic stability of the nucleus | ||||
#21-05-00 Video Runtime: 07:00 Solution: PC|Mac :: Android|iOS | (a) Calculate the nuclear binding energy per nucleon for the 79Kr nuclide (the atomic mass of 79Kr is 78.920083 amu). (b) A nuclear reaction that has been proposed as a potential source of energy is the fusion of the nuclides of hydrogen (1H, atomic mass 1.007825035 amu) and deuterium (2H, atomic mass 2.014101779 amu), producing the nuclide of a helium-3 (3He, atomic mass 3.01602931 amu). Calculate the energy of this reaction per gram of 3He produced? |