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14
votes
1answer
3k views

The bond in coordination complexes

This is a very basic question and I'm surprised it only just struck me. The nature of the bond in coordination complexes is a coordinate covalent bond. Only the ligand donates electrons for bond ...
2
votes
1answer
2k views

what is the name of the molecule that has the greatest number of different atoms? [closed]

What is the name of the molecule that has the greatest number of different kinds of atoms? For example, H2O is water has 2 different kinds of atoms which are H and O. For example, C6H12O6 is ...
10
votes
2answers
18k views

What's the relationship between Van der Waals forces and hydrophobic interactions?

A question on a past exam for a course I'm studying for asks: What's the relation between Van der Waals forces and hydrophobic interactions? From what I understand, Van der Waals forces are ...
3
votes
1answer
154 views

metal salt solutions g/l means hydrate or anhydrous

I want to redo an experiment. They've used Nickel chloride: 40 g/L Nickel chloride can be bought in two forms: anhydrous ($\ce{NiCl2}$) and hydrate ($\ce{NiCl2....
2
votes
2answers
1k views

Are there any safety guidelines for mixing sulfate with chloride?

Some ceramicists decorate pottery using soluble salts (usually chlorides and sulfates e.g. copper chloride, cobalt sulfate) which are used individually or mixed to produce different colors. I have ...
2
votes
1answer
321 views

Voltaic and electrolytic cells

Why more attractive metals will be oxidized? Aren't they being reduced, because they attract and receive electrons from negative polyatomic ions? So they will be anodes, where oxidization occurs. Why ...
1
vote
1answer
112 views

Why is it a good idea to put some salt in the bread dough?

The salt that you can typically find in a kitchen is the $\ce{NaCl}$, isn't this salt supposed to act as an antiseptic? I find a lot of recipes that suggest the addition of salt when preparing the ...
-2
votes
3answers
6k views

Why can't a potassium sulfate anion KSO4(-) exist in solution?

Please explain to me why $\ce{KSO4^-}$ doesn't exist as a molecular ion in (aqueous) solution. I couldn't find a reason why. I assumed if you took one $\ce{SO4^{2-}}$ and one $\ce{K^+}$ ion, then ...
3
votes
4answers
3k views

Where does the characteristic peak for phtalic acid diethyl ester at m/z 149 originate?

Which fragmentation is possible at this m/z value for phthalic acid diethyl ester? I tried McLafferty but it didn't solve my problem.
6
votes
1answer
136 views

How can I reduce Crystallization temperature of seed oil to be used in winter as biodiesel?

How can I reduce Crystallisation temperature of seed oil to be used in winter as biodiesel? The glycerol has been removed from the oil, and white spirit is used to reduce its viscosity.
2
votes
1answer
26k views

Predicting the pH of a weak acid and weak base solution

I know that it is possible to predict whether combinations of acids and bases will be acidic, basic, or neutral: weak acid (WA) and strong base (SB) reacts basic strong acid (SA) and and weak base (...
3
votes
1answer
23k views

at constant volume why the change of enthalpy doesn't equal the change of heat

At constant pressure $p=\text{const.}$, change of internal energy equals heat subtract work(PV). So, $q=\Delta E - pV$. So is the the change of enthalpy. So we say at constant pressure, the change of ...
6
votes
1answer
308 views

Calculation of the enthalpy change of reactions

First, I’m a high school student and I wonder why every textbook just tells you how to set up those equations and cancel them to get the entropy change but never tells you why you can cancel the same ...
1
vote
1answer
807 views

About the nomenclature: manganate or manganite?

I am a bit confused about the correct name of $\mathrm{LaMnO}_3$. Is it lanthanium manganate or lanthanum manganite? I was assuming that since $\mathrm{SrTiO}_3$ is called strontium titanate, $\...
2
votes
2answers
769 views

Concentration, how to determine grams of NaCl needed

Disclaimer: It has been a very long time since I have done any chemistry. My friend posted this question on social media, I've copy+pasted it here: Exactly $16.0~\mathrm{ml}$ of a solution A is ...
0
votes
2answers
188 views

Generally available fluid with good heat transport properties

I have designed a container which is heated up and has to heat up some tube-coils of water inside of it. This container is filled with a fluid that can help store and transfer the heat received from ...
2
votes
3answers
336 views

Heating CrCl3(bpy)3 — isomerism and ligand exchange

$\ce{CrCl3(bpy)3}$ (A) when heated forms (B) which has the formula $\ce{CrCl3(bpy)2}$ and has one free $\ce{Cl-}$ per mole of (B). B can react with ethylene diamine ($\ce{en}$) to form (C) which has ...
1
vote
2answers
6k views

Reaction involved in Combustion of Nitrocellulose-Nitroglycerine(NCNG) solid propellant?

I'm working on solid propellant based microthrusters and I am using NCNG as the solid propellant. I want to know the reaction taking place and the mass fraction of the products obtained on combustion ...
1
vote
1answer
76 views

Explain isotopic uranium/perchloric acid digestion [closed]

What is happening in this video? Can you explain this technically as well as in layman's terms? I'll summarize it. I see a technician moving fuming mixtures of presumably uranium and organic ...
6
votes
1answer
248 views

Mistake in Wikipedia article on fugacity?

The Wikipedia Article on Fugacity contains statement The contribution of nonideality to the chemical potential of a real gas is equal to RT ln $\phi$ Here $\phi$ is fugacity coefficient.I think ...
9
votes
1answer
2k views

How could alcohol be made into a powder?

In the news recently is 'Palcohol', powdered alcohol, that you add to water or existing liquids to make it alcohol. Presumably this would dissolve and break apart into alcohol and {some other compound}...
2
votes
3answers
517 views

Bond angles in PDB

people I've been trying to adjust the bond angles in a protein data bank (PDB) file, but I'm a novice when it comes to computing so I would like to ask your assistance. I have a file for metamizole, ...
1
vote
1answer
924 views

Multiplication of the reaction and Equilibrium constant

$$\begin{align}\ce{2A + 2B &-> 2C }\\ \ce{A + B &-> C}\end{align}$$ Why does the equilibrium constant change? And why the rate of the first reaction square the rate of the second? I ...
3
votes
2answers
14k views

Carbon monoxide detection without a detector

I have just been waken up by an alarm and found out that my neighbour did something terrible with his lighter. Luckily, there was no fire, only a plenty of smoke, and our flats were hermetically ...
2
votes
3answers
3k views

Major product formed when 1,1,1-trichloropropane is treated with aqueous KOH

What are (is) the product formed when 1,1,1-trichloropropane is treated with aqueous potassium hydroxide? I think the major product should be propionic acid, but I'm not sure.
2
votes
1answer
457 views

How can I carry out a titration to identify mercury in wastewater?

First, I would like to do a some form of extraction to only get the mercury, then followed by a titration to identify the concentration or the presence of mercury.
2
votes
1answer
1k views

Finding the enthalpy of formation of magnesium oxide

I have the following reactions: $$\begin{align} \ce{Mg(s) + 2HCl(aq) &-> MgCl2(aq) + H2(g)}\\ \ce{MgO(s) + 2HCl(aq) &-> MgCl2(aq) + H2O(aq)}\\ \ce{H2(g) + 1/2O2(g) &-> H2O(l)}\\ \...
1
vote
1answer
2k views

How can the 18 electron rule be used to explain that Fe(η5-C5H5)2 doesn't react with hydrogen but Ni(η5-C5H5)2 does?

Fe(η5-C5H5)2 does not react with hydrogen, but its nickel analogue, Ni(η5-C5H5)2 is readily hydrogenated to give Ni(η5-C5H5)(η3-C5H7). Use the 18 electron rule to explain this behaviour. My answer so ...
7
votes
2answers
2k views

Why does no Robinson Annulation occur after the Michael addition?

Under basic conditions a Michael addition reaction can be used to convert compound A into product C. Explain why no Robinson annulation cyclic product is observed? Compound A Product C ...
5
votes
1answer
254 views

Reaction of CpFe(CO)2Cl with phenyllithium

The reaction of $\ce{(C5H5)Fe(CO)2Cl}$ with an equimolar amount of $\ce{Li+[C6H5]-}$ gives a product. Draw its structure and apply the 18 electron rule. In a question I was given the molecular weight ...
1
vote
1answer
867 views

Reactions involving trimethylaluminium Al2Me6 [closed]

I need to write balanced equations describing the following reactions: one mole of $\ce{Al2Me6}$ with two moles of water excess of $\ce{Al2Me6}$ with silicon dioxide excess of $\ce{Al2Me6}$ with tin(...
8
votes
1answer
3k views

Possible methods for copper (II) reduction to copper (I)

How can I make $\ce{Cu2O}$ from copper? I am seeing if electrolysis is a good route (in the context of kitchen style chemistry) to cuprous oxide, instead of the traditional heating copper and ...
1
vote
1answer
4k views

Electrolysis of aqueous lead nitrate

When going through one of my chemistry textbooks, I saw that the electrolysis of aqueous lead nitrate led to oxygen being formed at the anode and lead being formed at the cathode. However, in school, ...
0
votes
2answers
429 views

Unexplained peak cluster in proton NMR trace?

I am working on a straight-forward NMR graph as part of my test prep. I have a pretty limited understanding of NMR, but I thoroughly read the chapter leading up to this practice question and am having ...
0
votes
1answer
6k views

How much heat is gained/released based off of equation?

Using this equation, $\ce{CaCl2(s) -> Ca^{2+}(aq) + 2Cl^{-}(aq)}$ and $\Delta H = - 325.0 \; kJ $ If you have 15.0 grams of the solid, how much heat is released or gained in kilojoules?
10
votes
2answers
4k views

Rate Constant Units and Eyring Equation

Rearranging the Eyring equation leads to the following: $$\Delta^\ddagger S^\circ = R \ln{\frac{k \times h}{{k_\text{B}}{T}}}+\frac{\Delta^\ddagger H^\circ}{T}$$ where $k$ is the rate constant, $h$ ...
5
votes
2answers
15k views

How to judge if a reaction is exothermic or endothermic

Mix $\ce{HCl}$ and $\ce{NaOH}$ together (reactants are at the same temperature) in a calorimeter. The temperature increases, and the book says it's an exothermic reaction. I don't get it. The ...
16
votes
4answers
86k views

Why do the melting and boiling points of the noble gases increase when the atomic number increases?

What causes the melting and boiling points of noble gases to rise when the atomic number increases? What role do the valence electrons play in this?
0
votes
1answer
26 views

Can energy savings be estimated from activation energy differences?

Imagine two companies X and Y. Both companies use very similar technical equipment to carry out a biotechnological process where a chemical reaction is catalyzed by an enzyme. Company X uses an enzyme ...
6
votes
1answer
83 views

When was oil discovered to be of biological origin?

Is there an article, book, some account of the discovery that crude oil came from decayed biological material?
2
votes
1answer
66k views

How do I find the final temperature using specific heat?

What is the final temperature of water and iron if a $30~\mathrm{g}$ piece of iron at $144~\mathrm{°C}$ was dropped into a calorimeter with $40~\mathrm{g}$ of water at $20~\mathrm{°C}$? Specific heat ...
2
votes
4answers
811 views

Is this endo or exothermic?

$$\ce{4Fe + 3O2 -> 2Fe2O3(s) + 1625~$\mathrm{kJ}$}$$ This should be endothermic because the energy is in the product. However, if the equation is viewed from the perspective of the reactant, it ...
1
vote
1answer
107 views

Is the end of a cigarette on fire when lit?

Is the end of a cigarette on fire when it is lit? Or is it smoldering? Is there a chemical difference between the two?
1
vote
2answers
2k views

Calculating the partition function based on molar heat capacity

Given the molar heat capacity of a partition function as a function of temperature, how would one determine the partition function? Say the molar heat capacity = $\alpha T^2$
1
vote
1answer
1k views

Bond angle of nitrous acid [duplicate]

Why are there two possible bond angles for the nitrous acid molecule? After perusing Wikipedia I found that there are both cis and trans forms of the nitrous acid molecule. I also note that the cis ...
1
vote
0answers
123 views

What is the relationship between migration and the potential of double layer theory?

Double layer theories like that of Gouy-Chapman give the electrostatic potential $\ \phi\ $ in solution. For a symmetrical electrolyte and small potential drops $\ \phi\left(x=0\right)-\phi\left(x\...
0
votes
1answer
702 views

How much heat (in J) is required to produce 2.0L of N2(g) at 77.36 K and 1.0 atm?

The only thing that is given is: The enthalpy of vaporization for $N_2(l)$ is 5.56 kJ/mol. There aren't any examples similar to this problem in the textbook. I only know how to get energy using: $...
1
vote
1answer
450 views

Proving RTln($a_i$) equal to non PV work done by system,where $a_i$ is activity

We know that chemical potential is defined as ${\mu}_i={\mu}_i^{standard}+RT\ln(a_i)$. Here $a_i$ is the activity of $i^\text{th}$ component of solution. In case of gases instead of $a_i$ it is $f_i$ (...
3
votes
0answers
184 views

How much hydrolysis will likely occur of the following bonds at pH 1-4 in the time period of 1-3 hours?

The bonds are: (I have given pictures of what I mean in case there's any ambiguity that I leave open in these questions. Also so that if you want to number the R groups you've got a head-start) ...
2
votes
1answer
61 views

How does the process of protein denaturatation work?

I know it's the proteins that somehow change their properties at some temparature. But what kind of change, in terms of molecule-level structure?

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