If your question is part of your high school or college/university homework, please use this tag. 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, conceptual hints. This tag may be applied to ...

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1
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1answer
17 views

Ideal gasses reaction under const temp and pressure

Conceptual problem: let $A + 2B \rightarrow C + 2D$ be a reaction under constant pressure (P) and temp (T), that goes all the way towards the products. A,B,C,D are ideal gases. let $\Delta H$ be the ...
3
votes
1answer
137 views

What is “mer”, the first ingredient in a type nail polish?

The first ingredient in a type of nail polish is "mer". What is this? Is it some kind of chemical? How is it used? How does it work?
1
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4answers
104 views

Equation for salt formation for Ammonium Oxalate?

I'm having trouble finding out the salt formation equation for $\ce{(NH4)2C2O4}$ I thought it was $\ce{NH3 + H2C2O4}$ but that doesn't seem to balance out. $\ce{HC2O4-}$ seems to work, but are ions ...
1
vote
0answers
23 views

Identify “decoupling sites” in Glucose Oxydase reaction

Given the following coupled reactions: $$\ce{Glucose + O2 + H2O + Glucose~Oxydase -> Gluconic~Acid + H2O2}$$ $$\ce{H2O2 + TMB(star) -> TMB}$$ Identify: A potential reagent or product that ...
1
vote
0answers
22 views

How to calculate the sulfanediide concentration at equilibrium in a saturated hydrogendisulfide solution at pH 6? [on hold]

What is the $\ce{S^{2-}}$ concentration in a saturated solution (0.10 M) of $\ce{H2S}$, in which the pH has been adjusted to 6.00 by the addition of $\ce{HCl}$? For $\ce{H2S}$, $K_{a1} = 1.1 \cdot ...
0
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0answers
20 views

Converting from wavelength of light to energy [on hold]

I am trying to solve the following problem: Gamma ray radiation falls in the wavelength region of $1.00\times 10^{-16}$ to $1.00\times 10^{-11}$ meters. What is the energy of gamma ray radiation ...
3
votes
1answer
32 views

How to I identify the diene and dienophile through retrosynthesis of a given compound?

I'm stuck one what to use to make this compound: my first attempt below
3
votes
2answers
43 views

Concept of moles [duplicate]

When I look at a question like "How many moles of $\ce{K}$ are in 1 mole of $\ce{KOH}$?", how is it that in 1 mol of $\ce{KOH}$ there is 1 Mol of $\ce{K}$ and x moles of $\ce{OH}$? how is it that 1 ...
2
votes
1answer
20 views

Salt formation for Iron(III) Sulfate

What is the salt formation for Iron(III) Sulfate? Wikipedia tells me that the production of Iron(III) Sulfate is: $$\ce{2 FeSO4 + H2SO4 + H2O2 → Fe2(SO4)3 + 2 H2O}$$ I was wondering if there was a ...
2
votes
1answer
52 views

How to calculate the concentration of NO at equilibrium?

$\ce{N2(g) + O2(g) <=> 2NO(g)}$, $K_c = 4.1 \cdot 10^{-4} (T=2000~^\circ\mathrm{C})$ What is $\ce{[NO]}$ when a mixture of $0.20~\mathrm{mol}$ $\ce{N2(g)}$ and $0.15~\mathrm{mol}$ ...
3
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0answers
17 views

How do you calculate a unit cell's dimensions from an XRD spectra?

My Inorganic lab had us do an XRD measurement, but I've never been explained how to interpret the data. Question Calculate the unit cell dimensions a,b, and c, for $\ce{YBa2Cu3O7}$ from the ...
0
votes
0answers
35 views

How to calculate the volume of HCl solution required to react with a given amount of magnesium? [on hold]

Reaction equation: $\ce{Mg + 2HCl \rightarrow MgCl2 + H2}$ Determine, through calculation, the volume of $0.5~\mathrm{mol/L}$ $\ce{HCl}$ solution required to react with $0.5~\mathrm{g}$ of ...
0
votes
0answers
39 views

How to calculate the rate constant at a certain temperature, given first order rate constants at different temperatures? [closed]

I have this problem that I am trying to study for my test: A reaction has first order rate constants of $4.82 \cdot 10^{-5}~\mathrm{s^{-1}}$ at $25~^\circ\mathrm{C}$ and $1.41 \cdot ...
2
votes
1answer
32 views

Deriving The Triple Point Temperature and Pressure as the following expression

$ΔH_{fus}, ΔH_{vap}, ΔH_{sub}$, as well as ($Tl,Pl$) and ($Ts,Ps$), which corresponds to the temperature and vapor pressure of liquid and solid phrase. My strategies is to use the Clausius-Clapeyron ...
4
votes
1answer
34 views

How is a free radical on allylic position more stable than at Benzylic position?

Came across the following question just now. Which is the most stable free radicle among the given species ( I am attaching the picture). I was totally baffled as the book claims the answer to be ...
0
votes
0answers
21 views

Calculate the pH [closed]

Ascorbic acid, $\ce{H2C6H6O6}$, or Vitamin C is present in many citrus fruits. It is a diprotic acid with the following Ka values: Ka1 = 7.9 X 10-5 and Ka2 = 1.6 X 10-12. Calculate the pH of a 0.63 M ...
1
vote
1answer
68 views

How to calculate the theoretical yield of a Diels-Alder reaction?

A Diels-Alder reaction happens between 9-Anthracenemethanol (208.26 g/mol) and N-Methylmaleimide (111.10 g/mol). I'm using 0.069 g 9-Anthracenemethanol (0.033 mol) and 0.11g N-Methylemaleimide ...
3
votes
1answer
66 views

How do I know that an acid and conjugate base are present in equimolar amounts?

Acetylsalicylic acid is a molecule in several popular drugs such as Magnyl and aspirin. Its pKa is 3.5, and I'm about to calculate the pH of a 0.010 M solution of acetylsalicylic acid. I've read up ...
0
votes
0answers
22 views

Stoichiometry for the Mn(VII) to Mn(II) reduction under acidic conditions [closed]

How would I balance the following reduction: $$\ce{a\ MnO4- + b\ H+ + c \ e- -> d \ Mn^2+ + e\ H2O}$$
0
votes
1answer
43 views

What is the ratio of oxygen to magnesium oxide, by mass? [closed]

The mass ratio of magnesium to magnesium oxide is 0.455 g magnesium/0.755 g magnesium oxide. 1.What is the ratio of oxygen to magnesium oxide, by mass? 2.What is the mass ratio of oxygen to magnesium ...
0
votes
0answers
23 views

How to calculate the bond energy from reaction energy? [closed]

The enthalpy change for the following reaction is $-81.1~\mathrm{kJ}$. Using bond energies, estimate the $\ce{H-Br}$ bond energy in $\ce{HBr(g)}$. $$\ce{2HBr(g) + Cl2(g) -> 2HCl(g) + Br2(g)}$$ ...
0
votes
0answers
25 views

How much heat is released in the combustion of ethylene? [closed]

Given the equation $$\ce{C2H4(g) + 3O2(g) -> 2CO2(g) + 2H2O(l) + 1411 kJ}$$ how much heat is released when $8~\mathrm{g}$ $\ce{O2}$ react?
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0answers
15 views

if molar heat of solution NaOH is -445.1 kJ/mol, how much heat in kJ will be released if 80g NaOH are dissolved in H2O? [closed]

if molar heat of solution $\ce{NaOH}$ is -445.1 kJ/mol, how much heat in kJ will be released if 80g $\ce{NaOH}$ are dissolved in $\ce{H2O}$? I really don't understand this concept.
0
votes
0answers
20 views

After 88.419 seconds 33.20 % of A had not reacted. What is the first order rate constant? [closed]

A. 1.247e-2 s-1 B. 1.892e-2 s-1 C. 5.416e-3 s-1 D. 8.216e-3 s-1 I have no clue on how to even start this problem please help!
0
votes
2answers
42 views

Relative percentage of isotopes [closed]

An unknown element Q has two unknown isotopes: 60Q and 63Q. If the average atomic mass is 61.5amu, what are the relative percentages of the isotopes?
0
votes
2answers
16 views

which method can be applied to separate ferrofluid liquid from oil?

I am 2nd year mechanical engineer student. Wanna know is there any substance,liquid or any other stuff to separate ferrofluid from oil after mixing them... Please give me answers..
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3answers
126 views

Can all water soluble ionic compounds conduct electricity?

I'm taking a first yer chemistry course at University, i am reading alot of contradicting things. Some people say that ionic compounds that are soluble in water are ALWAYS electrically conductive, ...
1
vote
1answer
44 views

How to calculate the oxidation state and the number of equivalents oxidized with YBa₂Cu₃O₇

I've hit some trouble with these calculations and need help sorting out confusion. In the lab we synthesized $\ce{YBa2Cu3O7}$, per the lab manual $\ce{Y, Ba, O}$ have the usual charges of +3, +2, and ...
1
vote
1answer
30 views

How to calculate the equilibrium concentration from initial concentrations of the substrates? [on hold]

Consider the following equilibrium: $$\ce{2NOCl~(g) <=> 2NO~(g) + Cl2~(g)}$$ with $K = 1.6 \cdot 10^{–5}$. $1.00~\mathrm{mol}$ of pure $\ce{NOCl}$ and $0.989~\mathrm{mol}$ of ...
7
votes
1answer
41 views

How do I synthesize 3-phenyl oxirane-2-carbaldehyde from chloroacetonitrile?

I start with the hydrolysis of the nitrile in carboxylic acid and esterification of this. After I use the Darzens' reaction (using benzaldehyde), then I reduce the ester function with DIBALH in ...
-2
votes
0answers
18 views

Which gas diffuses fastest from a rubber balloon? [closed]

An inflated balloon goes down because gas molecules can diffuse through the rubber. Four balloons are filled with different gases at the same temperature and pressure. Which balloon would go ...
3
votes
1answer
48 views

How can Nernst equation apply in this redox reaction?

$$\ce{CuSO4 + Zn \rightarrow ZnSO4 +Cu}$$ what is the cell potential of the voltaic cell with copper and zinc electrodes if the system is at 50 degrees and the solutions are both at 1 mol? How can it ...
0
votes
1answer
34 views

Why does the electron configuration for some elements not follow the diagonal rule?

I'm doing a high-school assignment, and I came across a question that I didn't quite understand. Explain how the electron configurations for the following elements do not follow the diagonal ...
1
vote
0answers
20 views

Does the normality of single and double displacement reactions match these numbers? [closed]

Does the normality of single and double displacement reactions match these numbers? Like a single would have n and a double 2n? Or am I thinking about this wrong.
2
votes
2answers
55 views

Finding Frequency Factor when raising temperature

The question is: A reaction rate doubles when the temperature increases from $25~^\circ\mathrm{C}$ to $40~^\circ\mathrm{C}$. Calculate $E_a$ and the frequency factor. I found the activation ...
1
vote
1answer
22 views

Is it possible to separate out (MgxCu1-x)2(CO3)(OH)2 into simply (MgxCu1-x)(CO3)?

Good afternoon, Here is the problem I am stuck with, in particular just the first part of it. I have calculated the moles (4.492 x 10-3 mol) and I am quizzed with regards to the equation that occurs. ...
0
votes
1answer
24 views

What happens when you react pure metals with solutions of salts? [closed]

Copper reacts with silver nitrate solution. It produces silver and a blue solid called copper nitrate, $\ce{Cu(NO3)2}$. On a piece of copper there's a coating of solid silver. ...
1
vote
1answer
28 views

How do I utilize Henry's Law Constant in this Question?

I have tried for several hours to answer this question with no luck. I believe I may be missing a couple of steps or I am not utilizing the given information properly. Nonetheless, some guidance will ...
-1
votes
1answer
97 views

A solution contains 750 g of ethanol and 85.0 g of glucose (180 gmol−1). The volume of the solution is 810.0 mL [closed]

A solution contains 750 g of ethanol and 85.0 g of glucose (180 gmol−1). The volume of the solution is 810.0 mL. Part 1) Determine the percent of glucose in the solution. I divided 85 g by 750 and ...
5
votes
2answers
48 views

Why does decreasing the pressure of the system increase the relative volatility of a binary solution?

In our teaching lab, we were posed with the following question as an exersize: If the boiling points of two compounds differ by 50 degrees C at atmospheric pressure, what will be the effect on the ...
1
vote
1answer
37 views

Spontaneity of reversible chemical reactions - Both sides?

Does the reversibility of a chemical reaction make it spontaneous from both sides also? (i.e.: forward & backward reactions) If not then is there any relationship between $\Delta G$ of forward and ...
0
votes
2answers
49 views

Can we force a reversible reaction in equilibrium to become a “complete” one? If so, will the equilibrium constant change?

It's said about reversible reactions that they never go to completion & I know that's because in reversible reactions, the mixture obtained in equilibrium is more stable than the extremes (i.e. ...
1
vote
0answers
34 views

How does an ice bath change the rate of an reaction?

If I had hydrogen peroxide decompose with the help of manganese dioxide and measured the time taken for the reaction to complete and the volume of oxygen collected. I will get a graph that looks like ...
3
votes
1answer
49 views

How to know it when I see a covalent network?

This is a well-known (better said: well-discussed) question in the internet. When you look for answers for popular questions, you usually see them with a variable degree of reliability and complexity. ...
1
vote
1answer
28 views

Determine which is more electronegative based on ionization energy

One of the questions I got wrong in my assignment is this one: X, Y and Z are three unknown elements whose first 5 ionization energies are given above. The question is which of the 3 is the most ...
3
votes
1answer
168 views

Why does Phosphorus trifluoride molecule have dipole moment?

My book says that from drawing the Lewis structure for the molecule below, you can conclude that it has dipole moment. Can someone please explain why? I understand that the dipole moment expresses ...
2
votes
1answer
45 views

Is there a difference between Joule coefficient and Joule-Thomson coefficient?

Is there a difference between the Joule coefficient and the Joule-Thomson coefficient? Also, I am having a hard time understanding what they mean.
3
votes
2answers
421 views

What's the pH of Vinegar when it generally contains 5% Acetic acid?

Vinegar generally contains 5% Acetic acid. We would expect the pH of vinegar to be approximately: a. 0 b. 3 c. 7 d. 9 e. 12 I don't have the key for this question, so I ...
0
votes
1answer
28 views

What is the S2- in 0.10 M hydrogen sulfide?

I found this question in one of the problem sets and I decided to try it, I keep getting 9.1E-8 as the answer and I thought this since this is a diprotic acid and I made two equations and I keep ...
2
votes
1answer
44 views

CaCl2 + H2O change in specific gravity of products - Why?

I am seeing a significant change in specific gravity of products upon addition of $\ce{CaCl2}$ to water. The mass and volume of what goes in doesn't match my total specific gravity of what comes out. ...