## Search found 136 matches

Thu Mar 12, 2020 10:17 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Textbook question 7.23
Replies: 2
Views: 88

### Textbook question 7.23

For part C, could someone please explain why, as pH increases, [OH-] increases, so the reaction rate decreases? a) What is the overall reaction for the following mechanism? ClO2 1 H2O ∆ HClO 1 OH2 HClO 1 I2 ¡ HIO 1 Cl2 HIO 1 OH2 ∆ IO2 1 H2O (fast equilibrium) (very slow) (fast equilibrium) (b) Write...
Thu Mar 12, 2020 10:10 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Textbook question 7.17
Replies: 4
Views: 95

### Textbook question 7.17

For part E, could someone please explain why adding a catalyst to accelerate the 3rd step only would have no effect on overall reaction rate? Refer to the illustration below for the reaction A S D. (a) How many steps does this reaction have? (b) Which is the rate- determining step in this reaction? ...
Mon Mar 09, 2020 4:25 pm
Forum: First Order Reactions
Topic: Textbook question 7B.15
Replies: 2
Views: 40

### Textbook question 7B.15

Could someone please explain how to get part c, 10.9 grams? I got that 0.777mols/L remain, but I'm having trouble converting this to grams Sulfuryl chloride, SO2Cl2, decomposes by first-order kinetics, and kr 5 2.81 3 1023 min21 at a certain temperature. (a) Determine the half-life for the reaction....
Mon Mar 09, 2020 2:49 pm
Forum: First Order Reactions
Topic: Textbook question 7B.3
Replies: 5
Views: 130

### Textbook question 7B.3

For part C, could someone please explain how to get [A]= 0.085 mols/L? I understand how to get 0.068mols/L, but I don't understand why you subtract it from the starting amount 0.153mol/L for A concentration Determine the rate constant for each of the following first- order reactions, in each case ex...
Mon Mar 09, 2020 2:07 pm
Forum: General Rate Laws
Topic: Textbook question 7A.17
Replies: 3
Views: 84

### Textbook question 7A.17

For part c, I keep getting 2.85, instead of 2.85*10^-12. But I got the correct answer for part d using 2.85. Is there a typo in the textbook? The following data were obtained for the reaction A 1 B 1 C S products: Initial concentration, [J]initial/(mmol·L21) Initial rate/ Experiment A B C ((mmol)·L2...
Tue Mar 03, 2020 11:46 am
Forum: Administrative Questions and Class Announcements
Topic: Solutions Manual Errors
Replies: 6
Views: 107

### Re: Solutions Manual Errors

Yes, I'm pretty sure there are other errors other than the ones that he listed in the document that he posted
Tue Mar 03, 2020 11:45 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: HW 6.63
Replies: 1
Views: 45

### Re: HW 6.63

If you use the equation Ecell = E°cell - RT/F * ln(10) * log[H+], then I don't think the number of moles of e- matters
Tue Mar 03, 2020 10:52 am
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: hw 6O1
Replies: 1
Views: 79

### Re: hw 6O1

Cathode: Ni2+(aq) + 2e- → Ni(s)
Anode: 2H2O(l) → O2(g) + 4H+ (aq) + 4e- (since the O in SO4 gets oxidized)
E°cell = E°cathode - E°anode
-0.23V - 1.23V = -1.46V
Tue Mar 03, 2020 10:49 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: text problem 6m.1
Replies: 1
Views: 42

### Re: text problem 6m.1

I'm pretty sure the anode is supposed to be the M2+/M
Tue Mar 03, 2020 10:48 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L 3 part c)
Replies: 2
Views: 59

### Re: 6L 3 part c)

They are separated with a comma because they're both in the same phase
Mon Mar 02, 2020 12:22 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Textbook question 6M.7
Replies: 3
Views: 55

### Re: Textbook question 6M.7

For this question, you would want to find the least reduction potential as that implies that it is better as an oxidizing agent and thus will be better at reducing other compounds. What was your method for trying to solve this problem? I arranged the metals in order of decreasing E/V according to a...
Sun Mar 01, 2020 11:09 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Textbook question 6.65
Replies: 4
Views: 106

### Textbook question 6.65

Could someone please explain how to do this problem? I'm mostly confused about which numbers to plug into which formulas.
What range (in volts) does a voltmeter need to have to measure pH in the range of 1 to 14 at 25 degreesC if the voltage is zero when pH =7?
Sun Mar 01, 2020 4:24 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Textbook question 6.57
Replies: 1
Views: 41

### Textbook question 6.57

Could someone please explain why you take the square root of K to get Ka?

Use the data in Appendix 2B and the fact that, for the half- reaction F2(g) 1 2 H1(aq) 1 2 e2 S 2 HF(aq), E8 5 13.03 V, to calculate the value of Ka for HF.
Sun Mar 01, 2020 1:13 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Textbook question 6N.7
Replies: 1
Views: 52

### Textbook question 6N.7

Could someone please explain why for part B, n=1 and not n=2? I got that the two half reactions were: H2(g)→2H+(aq)+2e- and 2H+(aq)+2e- →H2(g) Why is only 1 e- involved and not 2e-? Calculate Ecell for each of the following concentration cells: (b) Pt(s)|H2(g, 1 bar)|H1(aq, pH 5 4.0)||H1(aq, pH 5 3....
Sat Feb 29, 2020 11:48 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Textbook question 6N.3
Replies: 1
Views: 68

### Textbook question 6N.3

Could someone please explain for part C, how/why do you include the partial pressures of H2 and Cl2 gases in the lnQ?

Predict the potential of each of the following cells:
c. Pt(s)|Cl2(g, 250 Torr)|HCl(aq, 1.0 mol/L) || HCl(aq, 0.85 mol/L) | H2(g, 125 Torr)|Pt(s)
Fri Feb 28, 2020 11:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Textbook question 6M.7
Replies: 3
Views: 55

### Textbook question 6M.7

For this question, we are supposed to arrange the metals in order of decreasing E/V, right? For part A I keep getting Cu, Fe, Zn, Cr For part C I keep getting V, Ti, Al, U For part D I keep getting Au, Ag, Sn, Ni I'm not sure what I keep doing wrong? Arrange the following metals in order of increasi...
Thu Feb 27, 2020 11:52 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Textbook question 6L.7
Replies: 1
Views: 39

### Textbook question 6L.7

Could someone please explain for part C, how "KOH" got introduced into the cell diagram? It wasn't in the equation that was given. Write the half-reactions and devise a galvanic cell (write a cell diagram) to study each of the following reactions: C. Cd(s) + 2 Ni(OH)3 (s) → Cd(OH)2 (s) + 2...
Thu Feb 27, 2020 11:24 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Textbook question 6L.5
Replies: 1
Views: 35

### Textbook question 6L.5

Could someone please explain how to get the half reactions for part D of this question?

Write the half-reactions, the balanced equation for the cell reaction, and the cell diagram for each of the following skeletal equations:
D. Au+(aq) → Au(s) + Au3+(aq)
Thu Feb 27, 2020 10:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Textbook question 6L.3
Replies: 1
Views: 48

### Textbook question 6L.3

For part D, could someone please explain how to get the half reactions for this cell?

Write the half-reactions and the balanced equation for the cell reaction for each of the following galvanic cells:
D. Pt(s)|O2(g)|H+(aq)||OH-(aq)|O2(g)|Pt(s)
Wed Feb 26, 2020 10:47 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Midterm question Q3B
Replies: 3
Views: 143

### Midterm question Q3B

Could someone please explain why the correct answer is B? For the # of moles, I keep getting 0.1 moles in total for A, and then 0.2 moles in total for B, C, and D each Which combination of solutions of HCL and NaOH would produce the largest delta T? A. 50mL of 1M HCl with 50mL of 1M NaOH B. 50mL of ...
Wed Feb 26, 2020 10:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm question 4
Replies: 1
Views: 56

### Midterm question 4

Could someone please explain why solids are included in the equilibrium constant equation for this problem? The drug amphetamine is usually marketed at hydrogen bromide salt because it is much more stable in this solid form. When the drug is ingested as a salt (solid form), it enters the stomach, wh...
Wed Feb 26, 2020 8:22 pm
Forum: Balancing Redox Reactions
Topic: Textbook question 6K.3
Replies: 1
Views: 45

### Textbook question 6K.3

What are the half reactions for part D? How do you get the oxidation reaction from just Cl2 on the reactants side? D. Cl2(g) → HClO(aq) + Cl2(g) Balance each of the following skeletal equations by using oxidation and reduction half-reactions. All the reactions take place in acidic solution. Identify...
Tue Feb 25, 2020 10:12 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm question 3D
Replies: 1
Views: 51

### Midterm question 3D

At pH 6, what is the net charge for acetic acid, CH3COOH (pKa=4.75)?
Tue Feb 25, 2020 10:07 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Midterm question Q3B
Replies: 2
Views: 137

### Midterm question Q3B

Which combination of solutions of HCL and NaOH would produce the largest delta T?
A. 50mL of 1M HCl with 50mL of 1M NaOH
B. 50mL of 2M HCl with 50mL of 2M NaOH
C. 100mL of 1M HCl with 50mL of 2M NaOH
D. 100mL of 1M HCl with 100mL of 1M NaOH
Mon Feb 24, 2020 2:59 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Textbook question 5G.17
Replies: 1
Views: 67

### Textbook question 5G.17

Could someone please explain why the concentrations of reactants and products approach their own respective equilibriums? Also, why in the answer key is I2 the product and I the reactant?

Depict the progress of the reaction graphically (as in Fig. 5G.1) for the reaction in Exercise 5G.13.
Sun Feb 23, 2020 2:52 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: work
Replies: 8
Views: 99

### Re: work

Work is negative when energy is leaving the system
Sun Feb 23, 2020 2:49 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: max potential
Replies: 4
Views: 59

### Re: max potential

Maximum potential difference occurs when very little current flows. As the current approaches 0, the maximum potential difference converges to E (electromotive force of cell)
Sat Feb 22, 2020 2:29 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Textbook question 4.51
Replies: 1
Views: 42

### Textbook question 4.51

Using values in Appendix 2A, calculate the standard Gibbs free energy for the vaporization of water at 25.0 8C, 100.0 8C, and 150.0 8C. (b) What should the value at 100.0 8C be? (c) Why is there a discrepancy?
Sat Feb 22, 2020 2:28 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Textbook question 4.49
Replies: 1
Views: 82

### Textbook question 4.49

Could someone please explain the "reference point" concept?

Some entries for Sm8 in Appendix 2A are negative. What is common about these entries, and why would the entropy be negative?
Sat Feb 22, 2020 2:26 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Textbook question 4.45
Replies: 1
Views: 104

### Textbook question 4.45

For part E, could someone please explain what the answer key means by "dispersal of matter?"
The question was "What is the driving force for the dissolution of KNO3?"
Wed Feb 12, 2020 3:03 pm
Forum: Phase Changes & Related Calculations
Topic: 4.5
Replies: 2
Views: 106

### Re: 4.5

Find the amount of heat transferred to ice in 0.5hrs using q=mCdeltaT. You will get 3135J transferred in 0.5 hrs. Then use dimensional analysis to find how many joules are transferred in 10hrs. You get 62.7kJ transferred in 10hrs. Then divide 62.7kJ by 8.33 moles and get 7.53kJ/mol for enthalpy of f...
Wed Feb 12, 2020 3:00 pm
Forum: Student Social/Study Group
Topic: midterm location
Replies: 1
Views: 51

### Re: midterm location

It's on north campus towards the back end of the sculpture garden. It's a big white colored building.
Wed Feb 12, 2020 2:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess Law
Replies: 6
Views: 103

### Re: Hess Law

Given the main reaction, find the sum of the entropies, enthalpies, etc. of the reactants and products
Wed Feb 12, 2020 12:42 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Textbook question 4J.17
Replies: 2
Views: 49

### Textbook question 4J.17

Could someone please explain why for B and C you know that the reactions are spontaneous everywhere and nonspontaneous everywhere respectively? Why don't you calculate the maximum temperature cut off? Why are parts B and C different from part A of this question? Assume that DH8 and DS8 are independe...
Tue Feb 11, 2020 11:52 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Textbook question 4J.7
Replies: 2
Views: 42

### Textbook question 4J.7

Could someone please explain why the deltaH for part A is subtracts the Hf of products minus reactants? Why don't we add them together? Why is the correct answer -196.1kJ/mol and not -947.22kJ/mol? Calculate the standard reaction entropy, enthalpy, and Gibbs free energy for each of the following rea...
Thu Feb 06, 2020 12:25 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Textbook question 4B.9
Replies: 4
Views: 47

### Textbook question 4B.9

For parts A and D, why must w=0 in an adiabatic process?
Thu Feb 06, 2020 12:13 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A.9
Replies: 1
Views: 19

### Re: 4A.9

I'm not entirely sure if this answers your question, but the problem did say that no heat is lost to the surroundings
Thu Feb 06, 2020 12:00 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Textbook question 4B.3
Replies: 3
Views: 49

### Textbook question 4B.3

The internal energy of a system increased by 982 J when it was supplied with 492 J of energy as heat. (a) Was work done by or on the system? (b) How much work was done? For part b, I keep getting 490J, but the answer key in the back of the book says 90*10^2J? Could someone please explain how to get ...
Wed Feb 05, 2020 11:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Textbook question 4A.13
Replies: 5
Views: 61

### Textbook question 4A.13

A constant-volume calorimeter was calibrated by carrying out a reaction known to release 3.50 kJ of heat in 0.200 L of solu- tion in the calorimeter (q 5 23.50 kJ), resulting in a temperature rise of 7.32 8C. In a subsequent experiment, 100.0 mL of 0.200 m HBr(aq) and 100.0 mL of 0.200 m KOH(aq) wer...
Mon Feb 03, 2020 12:04 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Textbook question 4A.3
Replies: 2
Views: 61

### Textbook question 4A.3

Could someone please explain why part c is 8J and not 28J? Also how do you get 8J? Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump is 3.0 cm and the pump is depressed 20. cm with a pressure of 2.00 atm. (a) How much work is done in the compression? (b) Is...
Sun Feb 02, 2020 11:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook question 4D.23
Replies: 1
Views: 35

### Textbook question 4D.23

Calculate the standard enthalpy of formation of dinitro- gen pentoxide from the following data: 2 NO(g) 1 O2(g) ¡ 2 NO2(g) ¢H° 5 2114.1 kJ 4 NO2(g) 1 O2(g) ¡ 2 N2O5(g) ¢H° 5 2110.2 kJ and from the standard enthalpy of formation of nitric oxide, NO (see Appendix 2A). Could someone please explain why ...
Sat Feb 01, 2020 8:24 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook question 4C.3
Replies: 3
Views: 66

### Textbook question 4C.3

Could someone please explain how to get the correct answers for this question? For part a, I keep getting 330K and for part b, I keep getting 343K 4C.3 Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) ...
Sat Feb 01, 2020 8:22 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Textbook question 4D.9
Replies: 3
Views: 56

### Re: Textbook question 4D.9

That is correct the O2 and N2 are diatomic gases in their most stable form and thus their standard enthalpy of formation is zero. Using the enthalpies of formation we calculate that CO2 requires -393.51 kJ/mol while H20 requires -241.82. Given TNT's enthalpy of formation we calculate: 28(-393.51 kJ...
Sat Feb 01, 2020 8:19 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: how to solve thermodynamics problems
Replies: 2
Views: 45

### Re: how to solve thermodynamics problems

Something that might help is writing down what you are given from the problem and what you are trying to solve for. This may help you decide which formula to use and which units to try to get
Sat Feb 01, 2020 12:53 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Textbook question 4D.9
Replies: 3
Views: 56

### Textbook question 4D.9

Could someone please explain how to get the correct answer? The enthalpy of formation of trinitrotoluene (TNT) is 267 kJ?mol21, and the density of TNT is 1.65 g?cm23. In princi- ple, it could be used as a rocket fuel, with the gases resulting from its decomposition streaming out of the rocket to giv...
Sat Feb 01, 2020 12:22 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Textbook question 4D.3
Replies: 1
Views: 42

### Textbook question 4D.3

Could someone please explain how to get the correct answer for part b? I keep getting 2.06kJ The reaction of 1.40 g of carbon monoxide with excess water vapor to produce carbon dioxide and hydrogen gases in a bomb calorimeter causes the temperature of the calorimeter assembly to rise from 22.113 deg...
Sat Jan 25, 2020 1:50 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook question 4C.3
Replies: 2
Views: 69

### Textbook question 4C.3

What are the correct answers for this question? The answer key just says the answer is 373K, but there are four parts to this question. 4C.3 Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) at constant...
Thu Jan 23, 2020 7:41 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Value of Ka, Kw, Kb
Replies: 5
Views: 46

### Re: Value of Ka, Kw, Kb

Ka and Kb are specific to a reaction at a specific temperature
Thu Jan 23, 2020 7:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K value
Replies: 7
Views: 58

### Re: K value

I think you should try to exclude the x value if K is slightly less than 10^-3. But still make sure to check that the percent ionization is less than 5% for a valid approximation
Thu Jan 23, 2020 7:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Replies: 1
Views: 24

### Re: Quadratic Equation for [EQ]

I like to do the quadratic equation in small, separate parts to make sure I don't mess up. The first calculations I do are the b^2 and 4ac. The second set of calculations I do is solving for what is inside the radical and then taking the square root of it. After that, I add/subtract -b to/from that ...
Mon Jan 20, 2020 12:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 6D.13
Replies: 2
Views: 54

### Re: Textbook question 6D.13

Rank the following solutions in order of increasing pH: (a) 1.0 3 1025 m HCl(aq); (b) 0.20 m CH3NH3Cl(aq); (c) 0.20 m CH3COOH(aq); (d) 0.20 m C6H5NH2(aq). Justify your ranking.
Mon Jan 20, 2020 12:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 6.19
Replies: 2
Views: 33

### Re: Textbook question 6.19

Hemoglobin (Hb) molecules in blood carry O2 molecules from the lungs, where the concentration of oxygen is high, to the tissues where it is low (see the Interlude following Focus 5). In the tissues the equilibrium H3O1(aq) 1 HbO22 (aq) ∆ HHb(aq) 1 H2O(l) 1 O2(aq) releases oxygen. When muscles work h...
Fri Jan 17, 2020 8:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 6.19
Replies: 2
Views: 33

### Textbook question 6.19

Could someone please explain the reasoning behind part A in question 6.19?
Fri Jan 17, 2020 3:47 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 6D.13
Replies: 2
Views: 54

### Textbook question 6D.13

Could someone please explain how to find the pH for parts a and d?
What are the correct pHs for parts a and d?
Thu Jan 16, 2020 11:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 6D.5
Replies: 1
Views: 34

### Textbook question 6D.5

For part d for the percent protonation, I got 1.49% instead of 2.5%
I got the correct values for the pOH and pH though
Could someone please explain how to get 2.5%?
Wed Jan 15, 2020 11:41 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5.39
Replies: 4
Views: 87

### Re: 5.39

I found on the internet that the Kc value for the forward rxn is actually 5.9*10^-3. So, for the reverse rxn, the Kc value would be 1.69*10^2
Using these values, I got pretty similar values of concentrations as the solution manual
Wed Jan 15, 2020 3:38 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Textbook question 6B.11
Replies: 2
Views: 21

### Textbook question 6B.11

Could someone please explain how to get the answers to parts a.ii and b?
I understand how to get part a.i
Wed Jan 15, 2020 3:21 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Textbook question 6B.9
Replies: 1
Views: 31

### Textbook question 6B.9

Could someone please explain how to fill in the table for solutions 1 and 2?
I got that the concentrations were 1.50mol/L and 6.67*10^-15
I got that the pHs and pOHs for these two solutions were -0.18 and 14.18
Mon Jan 13, 2020 10:26 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Module 2 Question 27
Replies: 1
Views: 60

### Re: Module 2 Question 27

100g of C is 8.326 moles of C Set up an ICE table Initial C: 8.326/50 = 0.16652 Initial H2O: 2.5/50 = 0.05 Initial CO: 0 Initial H2: 0 Change: -x for C and H2O, +x for CO and H2 Equilibrium C: 0.16652-x Equilibrium H2O: 0.05-x Equilibrium CO and H2: both are x, which is given to be 0.04 Plug x=0.04 ...
Mon Jan 13, 2020 2:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5.39
Replies: 1
Views: 41

### Textbook question 5.39

For part A, I found the equilibrium concentrations when V=1L.
For part B, I found the equilibrium concentrations when V=0.5L.

For part A I got 0.01 for x instead of 0.0065
For part B I got 0.02 for x instead of 0.015

I'm not sure where I went wrong?
Mon Jan 13, 2020 2:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5.35
Replies: 2
Views: 33

### Textbook question 5.35

Could someone please explain how to get the correct answers for parts a and b?
Mon Jan 13, 2020 1:52 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Textbook question 5J.11
Replies: 3
Views: 45

### Textbook question 5J.11

Could someone please explain how we know that the reaction in part B is endothermic?
Mon Jan 13, 2020 1:39 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Textbook question 5J.5
Replies: 2
Views: 29

### Textbook question 5J.5

Could someone please explain why parts D and E have different answers? Why is part E not "no change" also?
Sat Jan 11, 2020 12:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Post assessment 2 question 30
Replies: 1
Views: 30

### Post assessment 2 question 30

A mixture of 2.5 moles H2O and 100 g of C are placed in a 50 L container and allowed to come to equilibrium subject to the following reaction: C(s) + H2O (g) ⇌ CO (g) + H2 (g). The equilibrium concentration of hydrogen is found to be [H2] = 0.040 M. Calculate the equilibrium constant Kc of this reac...
Sat Jan 11, 2020 10:22 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.27
Replies: 1
Views: 32

### Textbook question 5I.27

Could someone please explain how to get the answer for part C?
Sat Jan 11, 2020 9:13 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.15
Replies: 1
Views: 35

### Textbook question 5I.15

Could someone please explain how to find the equilibrium concentration of H2S? Why isn't is 0.2mols/L also?
Sat Jan 11, 2020 8:59 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.13
Replies: 2
Views: 32

### Textbook question 5I.13

Could someone please explain how to get the correct answers for parts b and c?
Fri Jan 10, 2020 3:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Example 5I.4
Replies: 4
Views: 42

### Example 5I.4

For this example, how do you know to find the partial pressures and not the concentrations at equilibrium?
Wed Jan 08, 2020 2:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.11
Replies: 1
Views: 41

### Textbook question 5I.11

Could someone please explain how to get part a? I keep getting 13.9 instead of 6.9
Wed Jan 08, 2020 2:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.3
Replies: 2
Views: 41

### Textbook question 5I.3

I keep getting 4.21*10^-6 mols/L
Tue Jan 07, 2020 10:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook example 5H.1
Replies: 2
Views: 28

### Textbook example 5H.1

Could someone please explain how to find the value of R in this example?
I understand how to get that T=673K, K=3.1*10^4, and Δnt= -1
Mon Jan 06, 2020 10:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5G.11
Replies: 2
Views: 35

### Textbook question 5G.11

Is it possible to problem 5G.11 without having read section 5G.4? Because the syllabus says to omit section 5G.4
Mon Jan 06, 2020 10:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5G.9
Replies: 2
Views: 36

### Textbook question 5G.9

Could someone please explain the reasoning behind the correct answer for part C?
Sat Dec 07, 2019 12:34 am
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 5340

### Re: MARSHMALLOW- FINAL REVIEW SESSION[ENDORSED]

For #1c on mini marshmallow, how do you know to choose NH4+ and not NO3- for the net ionic equation? Since they're both weak acids and bases
Mon Dec 02, 2019 1:25 pm
Forum: Naming
Topic: 9C.3
Replies: 4
Views: 90

### Re: 9C.3

a. K3[Cr(CN)6]
b. [Co(NH3)5SO4]Cl
c. [Co(NH3)4(OH2)2]Br3
d. Na[Fe(C2O4)2(OH2)2]
Mon Dec 02, 2019 1:20 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: H-atom energy levels
Replies: 1
Views: 110

### Re: H-atom energy levels

Using En=-hR/n^2, write this expression twice, and make one nfinal and one ninitial. Then, switch to the form E=R{1/n1^2 - 1/n2^2}. To solve for n2^2, divide both sides by R, subtract 1/n1^2, multiply by -1, take square root
Mon Dec 02, 2019 1:16 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D11 part c and d
Replies: 1
Views: 25

### Re: 6D11 part c and d

KF has F- (conjugate base of weak acid) which forms basic solutions
KBr has Br- (anion of strong acid) which has no significant effect on pH of solutions
Mon Dec 02, 2019 1:14 pm
Forum: Bronsted Acids & Bases
Topic: Lecture 12/2
Replies: 3
Views: 44

### Re: Lecture 12/2

I think he said weak acids and bases do affect pH
Mon Dec 02, 2019 1:12 pm
Forum: Calculating the pH of Salt Solutions
Topic: Textbook box 6E.1
Replies: 1
Views: 46

### Textbook box 6E.1

Could someone please explain how you know to use pKa1, pKa2, pKa3, etc. to find the pH?
Will you always be given these values, or do you need to know how to solve for pKa values?
Sat Nov 30, 2019 2:43 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Textbook question 6C.21
Replies: 1
Views: 42

### Textbook question 6C.21

For part b, why is formic acid stronger than acetic acid?
Sat Nov 30, 2019 1:05 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Textbook question 6B.9
Replies: 2
Views: 93

### Textbook question 6B.9

Why is the pH of acid #1 0.176? Why isn't it -0.176?
Isn't the formula for pH: -log[H3O+] ? So why isn't the pH negative after you plug in 1.50mols/L for the [H3O+]?
Sat Nov 30, 2019 11:30 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Textbook question 6B.3
Replies: 1
Views: 37

### Textbook question 6B.3

I understand how to get 1.6 for part A, but how do you get 1.7 for part B?
Sat Nov 30, 2019 10:54 am
Forum: Amphoteric Compounds
Topic: Textbook question 6A.17
Replies: 1
Views: 43

### Textbook question 6A.17

Could someone please explain why part d is amphoteric? Isn't Bi a metal, so why isn't it basic?
Thu Nov 28, 2019 2:27 pm
Forum: Naming
Topic: Iron as the central metal
Replies: 2
Views: 35

### Iron as the central metal

When do you write "ferrate," "ferrous," and "iron(oxidation state)" ?
Thu Nov 28, 2019 2:25 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination number of [Co(Ox)3]3-
Replies: 2
Views: 28

### Coordination number of [Co(Ox)3]3-

Could someone please explain why the coordination number of [Co(Ox)3]3- is 6?
If "ox" represents EDTA, which is hexadentate, why isn't the coordination number 18 because there are three Oxs?
Thu Nov 28, 2019 2:21 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Denticity
Replies: 2
Views: 46

### Denticity

Could someone please explain to determine the denticity of a ligand based on its Lewis structure?
Thu Nov 28, 2019 2:17 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Pka vs Ka
Replies: 10
Views: 182

### Re: Pka vs Ka

pKa represents various Ka values on a logarithmic scale, where pKa=-log[Ka] and p=-logbase 10
Thu Nov 28, 2019 2:16 pm
Forum: Naming
Topic: Ligand Order
Replies: 5
Views: 66

### Re: Ligand Order

If the overall charge is negative, put the ion in front of the [] brackets
If the overall charge is positive, put the ion after the [] brackets
Sat Nov 23, 2019 10:27 pm
Forum: Bronsted Acids & Bases
Topic: Fundamentals question J.9
Replies: 1
Views: 45

### Fundamentals question J.9

Do we need to know how to write net ionic equations?
Sat Nov 23, 2019 3:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Textbook question 9c.9
Replies: 1
Views: 35

### Textbook question 9c.9

Could someone please explain why the coordination number for part d is 6?
Sat Nov 23, 2019 3:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Textbook question 9c.5
Replies: 1
Views: 76

### Textbook question 9c.5

Could someone please explain how to determine which ligands are polydentate? I drew out all the Lewis structures for this question, but I don't know where to go from there
Sat Nov 23, 2019 2:26 pm
Forum: Naming
Topic: Textbook question 9C.1
Replies: 2
Views: 70

### Textbook question 9C.1

Could someone please explain the reasoning behind the name "aquapentacyanocolbaltate(III)" for part c?
Tue Nov 19, 2019 7:10 pm
Forum: General Science Questions
Topic: Test 2 Review
Replies: 8
Views: 220

### Re: Test 2 Review

What do we need to know for "lone pairs and the reason for their locations"? I'm not sure what this is referring to
Tue Nov 19, 2019 7:07 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Intermolecular Forces
Replies: 6
Views: 120

### Re: Intermolecular Forces

The size of the molecule affects intermolecular forces. If the molecule is large, it will have more attractive intermolecular forces, which can cause it to change phase and become more condensed (liquid, solid).
Tue Nov 19, 2019 7:02 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability
Replies: 9
Views: 224

### Re: polarizability

The higher polarizability of a molecule, the stronger intermolecular forces/attractions there will be, so it will be harder to break bonds. Which means its melting point and boiling point will be high.
Tue Nov 19, 2019 3:30 pm
Forum: Hybridization
Topic: Is hybridized orbitals all weighed equally in character?
Replies: 4
Views: 45

### Re: Is hybridized orbitals all weighed equally in character?

I am almost positive that yes, they are all weighed equally in character
Tue Nov 19, 2019 3:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.15
Replies: 1
Views: 48

### Re: 2E.15

I think you are just supposed to memorize that the bond angles are less than 90 and less than 120
Sun Nov 17, 2019 10:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook question 2.63 part b
Replies: 1
Views: 23

### Textbook question 2.63 part b

Could someone please explain why the bond angle for b is 109.5 degrees? Why isn't it 180 degrees/linear?
Sun Nov 17, 2019 4:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook question 2.63
Replies: 1
Views: 23

### Textbook question 2.63

Could someone please explain why angle c is 120 degrees? Why isn't it 180 degrees?
Fri Nov 15, 2019 12:14 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook question 2E.1
Replies: 4
Views: 82

### Re: Textbook question 2E.1

I'm still confused, what about trigonal planar molecules? Don't they have 120 degree bond angles, but no lone pairs?