If your question is part of your high school or college/university homework, please use this tag. Do not use this as the only tag on a question. It signifies that instead of a direct answer, care should be taken to explaining the steps to the solution, preferably sticking to just giving helpful, ...

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1answer
20 views

Why is 2-methyl-2,3-pentadiene achiral?

2-Methyl-2,3-pentadiene is achiral. Why? Centre of symmetry Plane of symmetry C2 axis of symmetry Centre and Plane of symmetry. I've drawn the structure: ...
-1
votes
0answers
6 views

calculations involving unit cell dimension [on hold]

copper crystal has a face centered cubic lattice structure.Its density is 8.93g/cm.what is the edge length of the unit cell?atomic mass of copper M=63.5g/mol
-1
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0answers
10 views

Chemical Kinetics Question with pressure [on hold]

This is the question ttp://i.stack.imgur.com/PXPLZ.jpg And here is the solution The problem is I am not sure if my answer is correct Can anyone help me in verifying it
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0answers
6 views

Does the rate of ion movment in a salt bridge affect the total voltage produced by a voltaic (Galvanic) Cell?

I was thinking that different salts used in a salt bridge in a voltaic cell may have different rates of flow (perhaps ionic radius or some other property effects the rate?) I was wondering, if some ...
-1
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0answers
12 views

How many milliiters of 6.0 mol/L stock solution are needed to prepare : [on hold]

How many milliiters of 6.0 mol/L stock solution are needed to prepare : a) 0.50 L of 1.0 mol/L HCL?
2
votes
1answer
42 views

How to derive Van't Hoff equation for Henry's constant

While studying about Henry's Law, I encountered this equation,I didn't know how to derive it so I searched about it and got nothing, I tried to substitute $H$ (Henry's const.) by $\gamma\cdot f_i$ ...
0
votes
1answer
29 views

How does a lower pH change the alcohol concentration of wine?

I have been told it that when the pH of wine is lowered the alcohol concentration will decrease because of Le Chatelier's Principle. Which states; if a equilibrium is disturbed by changing the ...
-2
votes
1answer
28 views

Stability between cyclopentdiene compound

What will be the order of stability? According the me it should be : Cyclopentadienyl anion > Cyclopentadiene > Cyclopentadienyl cation because the order of stability is aromatic > non-aromatic ...
0
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0answers
41 views

Amount of NO produced in reaction between PbS and HNO3

Lead(II) sulfide dissolves in excess nitric acid according to the equation below. Calculate the volume of $\ce{NO{(g)}}$ at $27 ^\circ \mathrm{C}$ and $1.10\ \mathrm{atm}$ produced from $4.7\ ...
0
votes
1answer
22 views

Amount of CO2 produced from burning carbon [on hold]

When carbon is burnt in excess oxygen, the only product is carbon dioxide. Calculate the volume of $\ce{CO2(g)}$ at $120~^\circ\mathrm{C}$ and $1.20~\mathrm{atm}$ produced from $2.8~\mathrm{g}$ of ...
1
vote
1answer
48 views

Number of stereoisomers of 3-ethyl-1-pentene-1,4-diol

I am trying to figure out how many stereoisomers this compound has. I know that there are two chiral carbon atoms, which allow $2\times2 = 4$ possible isomers. There is also a double bond which, as ...
1
vote
0answers
25 views

Entropy Change of Resistor

A very large swimming pool filled with water of temperature equal to $20\mathrm{^\circ C}$ is heated by a resistor with a heating power of $500\ \mathrm{W}$ for $20$ minutes. Assuming the water ...
0
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0answers
22 views

Size of Germanium compared to Silicon

Gallium has a smaller atomic radius than Aluminum because of the poor shielding effect in Gallium due to the presence of 3d orbital. However why does this not happen with Germanium and Silicon, ...
0
votes
1answer
33 views

Ka calculation confusion

(My assumption may be wrong so kindly explain me in simple terms). First of all I have learned that $K_\mathrm{a} = \frac{[\ce{H+}] [\ce{A-}]} {[\ce{HA}]}$ . Also I have been informed that ...
0
votes
0answers
31 views

Hybridization of Tetraamminecopper(II) sulfate

$\ce {Cu++} $ has 9 electrons and d orbital and is almost completely filled (except 1 electron vacant) and $NH3$ donates electron eventually forming Sp3 hybrid orbitals But it has square planar ...
1
vote
0answers
33 views

What was the purpose of this experiment and why did fructose react differently?

I did an experiment regarding the identification of a range of monosaccharides and disaccharides and wanted to know what the exact purpose of this experiment was and what is was testing. The ...
-3
votes
0answers
21 views

Help with calculations with degree of ionization [closed]

The degree of dissociation is 1,3% in 0,1 acetic acid soultion. At which concentration is this 90% I thought that i could solve for the concentration of protons, and then find out much it would be ...
0
votes
0answers
19 views

what is the bond order if chloro benzene?

my teacher taught me to first find the confirming/canonical structures then selecting a pair of atoms connected by a bond and then use the formula Total no of bonds present between the pair in all ...
0
votes
0answers
16 views

Density of gasses [closed]

Given that air is a mixture of N2(nitrogen) and O2(oxygen) with a volume ratio of 4:1 from 1 -5 choose that Idenifies a gas that has a larger density than air at the same temperature and pressure a. ...
0
votes
1answer
36 views

pH of aqueous HCl

Calculate the $\mathrm{pH}$ of a pure water in which it was added $\ce{HCl}$. $10^{-6}$ is the final concentration of $\ce{HCl}$. So what I did was to add the concentration of $\ce{H3O+}$ in ...
-3
votes
0answers
23 views

Mass stoichiometry question please help [closed]

Sodium thiosulfate reacts with bromine in alkaline solution according to the equation: $\ce {Na2S2O3(aq) + 4Br2(l) + 10NaOH(aq) -> 2Na2SO4(aq) + 8NaBr(aq) + 5H2O(l)}$ In order to completely ...
1
vote
1answer
19 views

How to calculate the amount of substance of barium sulfate that is precipitated?

Determine the amount (in mol) of barium sulfate that will be precipitated when $200.0~\mathrm{cm^3}$ of $0.450~\mathrm{mol\,dm^{–3}}$ barium nitrate solution is added to an excess of sodium sulfate ...
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votes
0answers
40 views

Which is a stronger base, methylamine or ethylamine? and why?

I think it is because of inductive effect. But not really sure. The pushing of the electron cloud towards the Nitrogen atom increases the energy of the lone pair of the nitrogen due to repulsive ...
1
vote
1answer
78 views

IUPAC name for citric acid

I was wondering what the name is of the following structure: I think it's something like ... 3-hyrodxypentanoic diacid However, I wasn't able to find how to name ...
1
vote
0answers
18 views

Mass stoichiometry question

Copper metal reacts with $\rm 7~mol.dm^{-3}$ nitric acid to produce nitrogen monoxide, among other products. The ionic equation for this reaction is: $$\ce{3Cu(s) + 2NO3- (aq) + 8H+ (aq) -> ...
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votes
2answers
30 views

Making a salt using metal oxide

Is this possible? Get a metal like Sodium and then you burn it to make Sodium Oxide because burning something is adding O2. Then you add the Sodium Oxide to an acid like Hydrochloric Acid and then ...
0
votes
1answer
22 views

How to calculate the new concentration of a solution after adding more solute and convert it to ppm?

My question is the following: $2~\mathrm{g}$ table salt is added to $0.5~\mathrm{m^3}$ water whose salt concentration is $10~\mathrm{mg\,L^{-1}}$. Compute the salt concentration of the mixture in ...
0
votes
0answers
9 views

Does the ionic radius of an ion affect its rate of flow in an electrolye?

Do Ions of different Ionic Radius' have different speeds or rates of flow in an electrolyte and thus produce differences in currents? If so, would ions with smaller Ionic radius' move faster or ...
7
votes
0answers
91 views

How to rationalise with MO theory that CO is a two-electron donor through carbon?

A question I am looking at is as follows: $\ce{CO}$ is isoelectronic with $\ce{N2}$. Sketch MO diagrams for $\ce{CO}$ and $\ce{N2}$. Point out key differences between the diagrams and use the ...
0
votes
1answer
42 views

How do primary alcohols react with dihydropyrans

Its related to aldehyde and ketone.Q.7 I think it might be formation of acetal or hemiacteal reaction but I am not sure about it. Can anyone also explain me the mechanism of this reaction. Thanks in ...
0
votes
1answer
41 views

How to calculate the total number of atoms in a mixture of mono- and biatomic gases [closed]

My homework is as follows: A gas mixture contains 33% $\ce{O2}$, 60% $\ce{N2}$, and 7.0% $\ce{He}$, as volume percent. Calculate the total number of atoms of all types of gases present in 5.0 L ...
3
votes
1answer
28 views

How would using Different Salts in a Salt Bridge Effect the Voltage Generated by Voltaic Cell?

If I use a range of different nitrate solutions (e.g. calcium nitrate, iron nitrate) for the salt bridge in a voltaic cell, what effect would it have on the flow of ions in the Voltaic cells? Will ...
0
votes
1answer
81 views

Can somebody please help me interpret this H NMR?

I am fairly new to NMR and require assistance to analyze and interpret the NMR I have provided (sorry for it being vertical). This is an unknown compound that I have derived during one of my lab ...
0
votes
1answer
34 views

Oxidation state of Cu and Fe in Chalcopyrite

What is the oxidation state of Cu and Fe in chalcopyrite($\ce{CuFeS2}$)? Some sites tell that $\ce{Cu(I)Fe(III)S2}$ and other tell $\ce{Cu(II)Fe(II)S2}$ Which is right? Background: I am 12th grader ...
0
votes
0answers
5 views

Which is a better way to calculate E-cell [duplicate]

Suppose we have these two half cell reactions. In order to calculate E(Cu_+1/Cu), what is a viable way to do it. I looked up resources on when to simply reverse one equation and add/subtract the ...
1
vote
1answer
37 views

Percent composition by volume of the reaction H2 + Br2 <=> 2HBr

For the reaction $\ce{H2(g) + Br2(g) <=> 2HBr(g)}$ at a certain temperature, $K=1$. Determine the composition (in per cent by volume) of the equilibrium reaction mixture if the initial ...
0
votes
0answers
40 views

Limiting reagent in reaction between calcium chloride and silver nitrate

Limiting and excess reactant problems are quite confusing. We just started the topic a week ago. Here's the problem from my assignment: A solution containing $20\ \mathrm{g}$ of calcium chloride ...
1
vote
2answers
91 views

Why isn't CH3OH the most basic if it contains OH?

I was asked to find the most basic solution from the following: $\ce{K2SO4}$ $\ce{CH3OH}$ $\ce{Na2CO3}$ $\ce{(NH4)2CrO4}$ $\ce{BaCl2}$ I know that I have to identify the solution that ...
1
vote
0answers
27 views

What are the differences between silicone with phenyl and silicone with methyl groups?

I'm doing a work on silicone polymers and my question is what is the difference, in therms of consistency and viscosity, and the chemical differences (properties) between benzenic silicone and ...
1
vote
2answers
84 views

What is the most common oxidation state of gold?

I had a test this morning which had the following question: What is the most common oxidation state for gold? +1 -1 +2 +3 My attempt: Since the electronic configuration of ...
0
votes
0answers
13 views

How to derive the molecular formula from its volume in the gas phase and mass [duplicate]

A $0.406\ \mathrm{g}$ sample of an unknown vapor occupies $294\ \mathrm{mL}$ at $140~\mathrm{^\circ C}$ and $847\ \mathrm{mmHg}$. The empirical formula of the compound is $\ce{CH2}$. What is the ...
0
votes
2answers
46 views

Acid/Base strength conceptual question [duplicate]

Is this statement true or false? HCl is a stronger acid than HF because F is more electronegative than Cl. Please explain. I'm thinking this is true. The reason being is that since F is more ...
5
votes
1answer
142 views

How to dialkylate a cyclohexene, and convert a carbonyl to an alkene?

I'm trying to design a synthesis of D from C. All I can think of is using $\ce{Me2CuLi}$ to add the methyl group to the alkene. I thought maybe then if isobutyl bromide was in the reaction mixture ...
4
votes
1answer
63 views

Stuck on Identification of Unknown 1H NMR and 13C NMR

I am currently trying to determine the structure of my unknown compound with both 1H NMR and 13C NMR spectra. My H NMR peaks: 1.16ppm-singlet (1H), 1.68ppm-singlet (3H), 1.75ppm-singlet (3H), ...
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vote
0answers
42 views

How to find the composition of unknown compounds based on the products formed by characteristic reactions of them?

$\ce{A1}$ and $\ce{A2}$ are two ores of metal $\ce{M}$. $\ce{A1}$ on calcination gives a black precipitate, $\ce{CO2}$, and water. On reaction with dilute $\ce{HCl}$ and $\ce{KI}$, $\ce{A1}$ gives ...
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votes
1answer
61 views

Which alcohols change CrO3/H2SO4 from orange to green? [closed]

Which of the following sets of compounds cannot turn a clear orange solution of $\ce{CrO3/H2SO4}$ to a greenish opaque solution? (More than one answer is correct) A) Ethanol B) ...
0
votes
1answer
36 views

How to calculate the amount of substance of nitrogen that dissolves in water?

The Henry's law constant for the solubility of $\ce{N2}$ gas in water at $298~\mathrm{K}$ is $10^5~\mathrm{atm}$. The mole fraction of $\ce{N2}$ in air is $0.8$. The amount of substance of ...
1
vote
0answers
15 views

Moles/Volume Calculation and Molecular formula (using volume/mass?) [closed]

$\ce{X}$ is a hydrocarbon. When $\ce{X}$ is completely burned in air, $0.50\ \mathrm{mol}$ of $\ce{X}$ produce $60~\mathrm{dm^3}$ of carbon dioxide and $3\ \mathrm{mol}$ of water at r.t.p. Deduce ...
2
votes
0answers
42 views

Testing for nitrate ions with NaNO3

When we use Devarda's test on $\ce{NaNO3}$ solution (we add $\ce{NaOH}$ and $\ce{Al}$ powder, heat the mixture, and produce ammonia), what is the equation of the process? I understand that $\ce{Al}$ ...
1
vote
2answers
42 views

What's the Kp value?

A mixture of $1\ \mathrm{g}$ of $\ce{H2(g)}$ and $1.06\ \mathrm{g}$ $\ce{H2S(g)}$ in a $0.5\ \mathrm{L}$ flask come to equilibrium at $1670\ \mathrm{K}$. At equilibrium, there are $8\times10^{-6}\ ...