
Concept explainers
The methane molecule, CH4, has the geometry shown in Figure 2.17. Imagine a hypothetical process in which the methane molecule is "expanded, " by simultaneously extending allfour bonds C-H bonds to infinity. We then have the process:
(a) Compare this process with the reverse of the reaction thatrepresents the standard enthalpy of formation of CH4(g).
(b) Calculate the enthalpy change in each case. Which is themore endothermic process? What accounts for the difference inΔHo values? (c) Suppose that 3.45 g CH4(g) reacts with1.22 g F2(g), forming CH4(g) and HF(g) as sole products. What is the limiting reagent in this reaction? If reaction occurs at constant pressure, What amount of heat is evolved?

Want to see the full answer?
Check out a sample textbook solution
Chapter 5 Solutions
Chemistry: The Central Science (13th Edition)
- How many signals do you expect in the H NMR spectrum for this molecule? Cl CI CI Write the answer in the table below. Also, in each of the drawing areas below is a copy of the molecule, with H atoms shown. In each copy, one of the H atoms is highlighted red. Highlight in red other H atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: Remember, a multiplet is considered one signal in the 'H NMR spectrum. B Number of signals in the H NMR spectrum. For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional H atoms to highlight in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No…arrow_forwardThe alcohol group is a poor leaving group. Explain how reactions with alcohols are carried out if the -OH isn't favorable to leave.arrow_forwardHow many signals do you expect in the H NMR spectrum for this molecule? Br Br Write the answer below. Also, in each of the drawing areas below is a copy of the molecule, with Hs shown. In each copy, one of the H atoms is colored red. Highlight in red all other H atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: In this question, any multiplet is counted as one signal. Number of signals in the 'H NMR spectrum. ☐ For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional Hs to color in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional Hs to color in bottom molecule…arrow_forward
- How many signals do you expect in the 'H NMR spectrum for this' molecule? CI CI Write the answer in the table below. Also, in each of the drawing areas below is a copy of the molecule, with H atoms shown. In each copy, one of the H atoms is highlighted red. Highlight in red all other H atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: Remember, a multiplet is considered one signal in the 'H NMR spectrum. Number of signals in the 'H NMR spectrum. Π For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional H atoms to highlight in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right.…arrow_forwardHow many signals do you expect in the 'H NMR spectrum for this molecule? Br Write the answer below. Also, in each of the drawing areas below is a copy of the molecule, with Hs shown. In each copy, one of the H atoms is colored red. Highlight in red all other atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: In this question, any multiplet is counted as one signal. Number of signals in the H NMR spectrum. For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. ☐ No additional Hs to color in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional Hs to color in bottom molecule…arrow_forwardHow many signals do you expect in the H NMR spectrum for this molecule? CI CI Write the answer below. Also, in each of the drawing areas below is a copy of the molecule, with Hs shown. In each copy, one of the H atoms is colored red. Highlight in red all other H atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: In this question, any multiplet is counted as one signal. Number of signals in the H NMR spectrum. For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional Hs to color in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional Hs to color in bottom molecule…arrow_forward
- How many signals do you expect in the 'H NMR spectrum for this molecule? Write the answer in the table below. Also, in each of the drawing areas below is a copy of the molecule, with H atoms shown. In each copy, one of the H atoms is highlighted red. Highlight in red all other H atoms that would contribute to the same signal as the H already highlighted red. Note for advanced students: Remember, a multiplet is considered one signal in the 'H NMR spectrum. Number of signals in the H NMR spectrum. For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No additional H atoms to highlight in top molecule For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. No…arrow_forwardAre the atomic mass and atomic weight of an element equal if that element has no isotopes?arrow_forwardDifferentiate between atomic mass and atomic weight.arrow_forward
- Study this 'H NMR spectrum, and then answer the questions about it in the table below. 1.0- 0.5- 0.0 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 What unit symbol should be written on the horizontal axis? What is the chemical shift & of the quartet? If there is no quartet, just check the box instead. Give your answer to 2 significant digits. What is the chemical shift & of the signal immediately upfield of the doublet? If there is no doublet, or no signal upfield of it, check the box instead. What is the chemical shift 8 of the least deshielded proton? If you can't tell without more information, check the box instead. A 8=0 There is no quartet. No such signal. 8=0 Need more information. Explanation Check 2025 McGraw Hill LLC. All Rights Reserved. Terms ofarrow_forwardKinetics and Equilibrium = Calculating the solubility of an ionic compound when a common ion is... Calculate the solubility at 25 °C of PbCO 3 in pure water and in a 0.0090 M Pb (NO3), solution. You'll find K Round both of your answers to 2 significant digits. solubility in pure water: solubility in 0.0090 M Pb(NO3)2 solution: Explanation Check 口: g 口: x10 Х sp data in the ALEKS Data tab. 1/3 Ashley ✓ Solubility product constants (Ksp) ✓ HgS 4.00×10-54 Hg2SO4 6.5×10-7 PbBr2 6.60×10-6 00. PbCl 2 PbCO3 1.70×10-5 18 PbCrO4 7.40×10-14 2.00×10-14 Ar PbF2 3.3×10-8 PbI2 9.8×10-9 Pb(IO3)2 3.69×10-13 PbS 3.40×10-28 PbSO4 2.53×10-8 MgCO3 6.82×10-6 MgF2 5.16×10-11 Mg(OH)2 5.61×10-12 Mg3(PO4)2 Mn(OH)2 MnS -24 1.04×10¯ NiCO3 1.60×10-13 3.00×10-14 1.42×10-7 MOUN 16 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibilityarrow_forwardFor each of the molecules below, highlight each of the positions on the benzene ring that you expect will be most reactive towards electrophilic aromatic substitution. OH o so a NH₂ G ¿ Explanation Check 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use Privacy Cearrow_forward
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistry by OpenStax (2015-05-04)ChemistryISBN:9781938168390Author:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark BlaserPublisher:OpenStax
- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning





