All Questions
Tagged with textbook-erratum or erratum
119 questions
53
votes
2
answers
17k
views
Regioselectivity of acid-catalyzed ring-opening of epoxides
Not to be confused with what is the mechanism of acid-catalyzed ring opening of epoxides.
What is the correct order of regioselectivity of acid-catalyzed ring-opening of epoxides: $3^\circ$ > $2^\...
- 43.2k
20
votes
4
answers
13k
views
How many Ga atoms are connected to one As atom in solid gallium arsenide?
In Boylestad and Nashelsky's Electronic Devices and Circuit Theory, the structure of GaAs is shown as follows:
Arsenic is shown making five covalent bonds to neighbouring gallium atoms.
However, I ...
- 712
19
votes
2
answers
37k
views
What is the difference between molar conductance and molar conductivity?
I'm learning (or at least trying to learn) about electrochemistry, but a major obstacle to that, is that different books I refer use different terms for the same symbols. So in a last ditch attempt to ...
- 18.8k
16
votes
2
answers
2k
views
Definition of the B3LYP functional in common QC programs
I wanted to use custom functionals with Gaussian and came up with some interesting definitions of the B3LYP functional within Gaussian, Orca and Turbomole, ...
$$\small\begin{array}{lcccccc}
\hline
...
14
votes
2
answers
6k
views
Configuration of chiral center in cocaine
I couldn't get the absolute configuration for the chiral center I marked. I got R, but according to my answer key it is apparently S. Would really appreciate an explanation.
- 149
11
votes
1
answer
29k
views
Is an ester or a ketone more acidic?
Two organic chemistry textbooks I've read (by Bruice and by Tandon) say:
Esters are more acidic than ketones, because the resonance between the two oxygen atoms gives less opportunity for the ...
- 155
10
votes
1
answer
21k
views
Are all ionic compounds salts?
According to Wikipedia:
A salt is an ionic compound that can be formed by the neutralization
reaction of an acid and a base.
Are all ionic compounds salts? Are all salts ionic compounds?
- 111
10
votes
1
answer
188
views
Are the tars in cannabis considerably more dangerous than those in tobacco?
The claim that "the tars in cannabis are considerably more dangerous than those in tobacco" is made in Patricks An Introduction to Medicinal Chemistry (4th edition, p. 169). It's just a simple one ...
- 6,263
9
votes
2
answers
1k
views
Orientation of external cell when voltage is supplied by it to voltaic cell so as to oppose its cell potential
Given below is a page from our Chemistry Textbook:
As it can be seen, the direction of $E_{ext}$ in figure $3.2(c)$ is opposite to the direction in figures $3.2(a)$ and $3.2(b)$.
I understand that $...
- 159
9
votes
1
answer
3k
views
Planes of Symmetry and Chirality
I am trying to identify whether the following objects possess planes of symmetry or not, but my answers seem different, from the textbook solutions (Klein Organic Chemistry 2e, Page 220, Question 23). ...
- 631
9
votes
2
answers
8k
views
Why can't I dry/concentrate ethanol using calcium chloride ... or can I?
My (very unreliable) school textbook tells me:
Lower alcohols form a solid derivative with certain metal salts.
and,
It is for this reason that ethanol cannot be dried/concentrated using ...
- 18.8k
8
votes
2
answers
3k
views
How to calculate the potential via Hess's law? Is my textbook wrong about this?
Given the two reduction half-reactions for the following fuel cell, determine the standard cell potential $E^\circ_\mathrm{cell}$,
$$\ce{CH4 (g) + 2 O2 (g) + 2 OH- (aq) -> CO3^2- (aq) + 3 H2O}.$$
...
- 720
8
votes
1
answer
2k
views
Does aldol condensation give different products in different conditions?
I know the mechanism of aldol condensation and general method to determine products in crossed aldol reactions, or reactions between dissimilar molecules. But the following statement in my class notes ...
- 6,825
7
votes
3
answers
13k
views
Are these reaction equations for the formation of the brown ring complex correct?
\begin{align}
\ce{NO3- + 3Fe^2+ + 4H+ &-> NO + 3Fe^3+ + 2H2O}\tag{1}\\
\ce{[Fe(H2O)6]^2+ + NO &-> \underset{\text{(brown)}}{[Fe(H2O)5(NO)]^2+} + H2O}\tag{2}
\end{align}
The above are ...
- 931
7
votes
1
answer
176
views
Is there an error at page 138, 4.4 of Introduction of Computational Chemistry 3rd Edition?
Firstly, I found the RHF expansion of $\Phi_2$ and $\Phi_3$ is not symmetric at equation (4.29). Then I expand $\Phi_2$ by myself, the results showed it's
$
\Phi_2 = (\chi_A\chi_A-\chi_B\chi_B)(\alpha\...
- 181
7
votes
1
answer
930
views
Boiling point of oxygen
I am studying chemistry from the book titled "Fundamental Chemistry for Cambridge O Level" written by Rosemarie Gallagher and Paul Ingram.
On page 17, it states that
oxygen boils at −219 °C and ...
user93613
7
votes
2
answers
6k
views
Why is glycine hydrochloride more acidic than chloroacetic acid?
I cannot figure out why glycine hydrochloride is more acidic than chloroacetic acid. Could I have figured this out from a $\mathrm pK_\mathrm a$ table and maybe am just not seeing it? On the table I ...
- 149
6
votes
3
answers
16k
views
kJ per mole or kJ per 2 moles?
From Chemguide:
Here is a simple reaction between hydrogen and oxygen to make water:
$$\ce{2 H2(g) + O2(g) -> 2 H2O(l)} \quad \Delta_\mathrm{r}H^\circ = \pu{572 kJ mol^-1}$$
First, notice that ...
- 3,292
6
votes
2
answers
438
views
Error in formula for the solution to a chemical problem
The problem in my textbook goes like this:
Burning $0.68\ \mathrm{g}$ of an unknown substance, we obtained $1.28\ \mathrm{g}$ of sulfur oxide (IV) and $0.36\ \mathrm{g}$ of water. Find the chemical ...
- 3,292
6
votes
1
answer
48k
views
How to identify a redox reaction?
Which balanced equation represents a redox reaction?
\begin{align}
&\mathrm{A.} &\ce{AgNO3 + NaCl &-> AgCl + NaNO3} \\
&\mathrm{B.} &\ce{BaCl2 + K2CO3 &-> BaCO3 + 2KCl} ...
- 79
6
votes
1
answer
945
views
Bond-Line Structure for an Alkane
My textbook tells me the following structure is 2,2,5-trimethylpentane. I try to change the parent group in different ways so as to maximize the number of substituent groups, but I think the maximum ...
- 631
6
votes
3
answers
1k
views
Is this textbook bonding picture of hybridization in ethene wrong?
Regarding the above picture, why is the $\ce{C-C}$ $\sigma$ bond composed of two $\ce{sp^2}$ orbitals while the $\ce{C-H}$ $\sigma$ bonds composed of $\ce{sp^3}$ hybrid orbitals? I don't see why; I ...
- 19.2k
6
votes
1
answer
149
views
Enantioexcess for a non-chiral molecule?
I am trying to understand this quote in a section on "Biotransformations of Organic Molecules" from a handbook I am reading:
[...] Euglena gracilis could convert acetophenone to 2-...
- 1,638
6
votes
1
answer
2k
views
Why are 3 equivalents of organolithium needed in synthesis of ketone from carboxylic acid?
For the reaction of a carboxylic acid and organolithium reagents to synthesise a ketone, Clayden's, on p 219, mentions:
Notice that three equivalents of organolithium are needed in this reaction: ...
- 10.8k
6
votes
2
answers
437
views
2,4-dinitrophenyl hydrazine test
I found this reaction over here:
which illustrates the carbonyl test but looks fuzzy.
Assuming that the R in the product is a typo for H, I couldn't conserve the number of Nitrogen atoms.
...
- 702
6
votes
1
answer
3k
views
Constructing a Walsh diagram of AH2
According to Wikipedia, for the $\ce{AH2}$ Walsh diagram:
and the Walsh diagram in Shriver and Atkins Inorganic Chemistry, the $a_1$ orbital sinks in energy going from 90 to 180°. Furthermore, the $...
- 173
6
votes
1
answer
665
views
Is this really a comparison of the absolute energies in the reaction energy profile for ester formation?
In Clayden et al., Organic Chemistry, p. 332, the authors compare the reaction energy profile for ester formation from a) acyl chloride and b) anhydride:
They then write:
The energy levels of the ...
- 805
6
votes
1
answer
740
views
Is these a pair of diastereomer or identical compound?
I attempted on this question (e) and found out that they are diastereomers, but the answer from the book is that they are identical. I worked out the configuration at each of the centres for the ...
- 381
6
votes
2
answers
2k
views
Factors affecting mass of a gas-evolving reaction mixture over time
Excess magnesium was added to a beaker of aqueous hydrochloric acid on a balance. A graph of the mass of the beaker and contents was plotted against time (line 1).
What change in the experiment could ...
6
votes
1
answer
3k
views
Elimination from Vinylic Halides
Vinylic halides do not show nucleophilic substitution at all, because of their stability due to resonance. But elimination to form alkynes is possible. No nucleophile at all can displace the halide ...
- 2,755
6
votes
1
answer
3k
views
Why is tert-Butyl (tBu) often not listed as protecting group for alcohol?
I am not seing tBu listed as alcohol protection group in all of these places:
https://en.wikipedia.org/wiki/Protecting_group#Alcohol_protecting_groups
http://www.synarchive.com/protecting-group/
http:...
- 627
6
votes
1
answer
151
views
Why would hexacyanidocobaltate(II) be uncommon while pentacyanidoaquacobaltate(II) is common?
In Huheey's Inorganic Chemistry it is written that hexacyanidocobaltate(II) is uncommon but pentacyanidoaquacobaltate(II) is common. Something is mentioned about Jahn-Teller distortion, but I don't ...
user14874
5
votes
2
answers
19k
views
Correct equation for Ionic Conductivity (λ) in Solutions?
We haven't started on Electrochemistry at school yet, but I did manage to find some time to read up on the topic. One thing I've noticed from when I started, is that different books and sites use ...
- 18.8k
5
votes
1
answer
1k
views
Is Nitroglycerine a Nitro Compound or an Ester?
I looked up nitroglycerine in a science dictionary (Oxford Dictionary of Science, 2003), and it explicitly mentions that nitroglycerine is an ester and not a nitro compound.
However my teacher told ...
- 18.8k
5
votes
2
answers
11k
views
Acid catalysed mechanism of the addition of alcohols to alkenes
I believe that this mechanism is false.
The protonated ether would in my opinion give a proton to methanol rather than $\ce{H2SO4}$ because the protonated $\ce{CH3OH}$ is more stable than $\ce{H2SO4}$...
- 1,845
5
votes
1
answer
424
views
Mechanism for Diels–Alder of alkene with substituted thiophene sulfone with loss of sulfur dioxide
I came across a synthesis of centrohexaindane that has the following steps:
This is a Diels–Alder reaction that gives an aromatic ring. I know that alkynes will give this reaction as follows:
But in ...
- 460
5
votes
1
answer
5k
views
Is it a "Bary center" or a "Bari center"?
(Studying Coordination Chemistry, "Crystal Field Theory" at school)
Apparently, different sources spell this differently.
The Wikipedia article on Crystal Field Stabilization Energy, calls it the "...
- 18.8k
5
votes
1
answer
504
views
Energy of Eclipsed Interactions
I am asked to identify the highest and lowest energy conformations for the following bond-line structure (I think it is 2,2-dimethylbutane). I drew a Newman projection (for all 6 conformations) and ...
- 631
5
votes
0
answers
114
views
Is there a mistake in diagramatic representation of RS perturbation theory described in Szabo and Ostlund textbook?
I'm trying to understand rules of the diagrammatic representation of the many body perturbation theory that described in Szabo and Ostlund "Modern Quantum Chemistry" textbook. One of the ...
- 51
5
votes
0
answers
161
views
Why is the carbon atom omitted from the molecular formula?
In my chemistry textbook, the following reaction was given:
I have two questions related to the marked in orange boxes/parts of the image:
Why is the molecule symbolized by $\ce{(CH3)3Cl}$ instead ...
- 67
5
votes
0
answers
905
views
Is phosphorus trichloride really a stronger Lewis acid than antimony pentafluoride?
The following was a question from the ETS Chem GRE guide and apparently this was an actual question on an exam a few decades ago. Unfortunately, no explanation for the answer was given, and I couldn't ...
- 1,143
4
votes
2
answers
3k
views
What is the product of alpha decay of curium-226?
What product is formed when curium-226 undergoes alpha decay?
Curium has atomic number 96. Since alpha decay decreases the number of protons and neutrons by 2, the product formed has atomic number 94 ...
- 1,398
4
votes
2
answers
15k
views
Does fumaric acid form stronger hydrogen bonds than maleic acid?
My book claims:
Fumaric acid can form intermolecular hydrogen bonds (strong) while maleic acid forms intramolecular hydrogen bonds (weak), hence fumaric acid has higher boiling point than maleic ...
- 51
4
votes
1
answer
1k
views
MolView is unable to generate correct 3D structure for hydroxypropadiene
MolView is unable to generate the correct structure of hydroxypropadiene. It instead generates the structure of acrolein (which has the same molecular formula). Why is this so? Is it because ...
- 6,348
4
votes
2
answers
351
views
Interpretation of 1H-NMR spectra for Z-ochtodenol
I'm struggling to understand the 1H-NMR data for this compound. I managed to find the compound using the data I had, but at the end I can't assign the peaks properly.
My confusions are:
Shouldn't ...
- 587
4
votes
1
answer
5k
views
Why is sand/glass polar? How does lattice structure change polarity?
The molecular geometry of sand is linear. Dipole moment is thus cancelled.
But we all know from the meniscus water makes with glass that the dipole-dipole/H-O attraction between sand and water is ...
- 379
4
votes
2
answers
3k
views
What is the expected product in the reaction of hydrogen chloride with allylbenzene?
Shouldn't it be 4th option since since the carbon attached to the ring is secondary as well as resonance stabilized?
- 185
4
votes
3
answers
1k
views
Does manganese reacts with water at "not" standard conditions?
In my answer, I stated that manganese is said to not react with water under normal conditions although some sources say it reacts with water to liberate hydrogen gas. Does it implies that it reacts ...
- 26.8k
4
votes
1
answer
810
views
Can a bond be electrophilic or nucleophilic?
The indicated bond is:
A) Nucleophilic because it is electron-deficient.
B) Electrophilic because it is electron-rich.
C) Nucleophilic because it is electron-rich.
D) Electrophilic because it is ...
- 51
4
votes
1
answer
2k
views
Which is really water soluble, amylose or amylopectin？
In my textbook it was written that amylose is more water soluble than amylopectin. But as I searched for the reason I found a totally opposite information.
https://pubs.acs.org/doi/pdf/10.1021/...
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