CHEMISTRY COMMUNITY

Nikhil_Madan_3C

This is because the numbering must follow the direction of the double bond. Naming it as 2,3,4,4-tetramethylcyclo-1-hexene would make the number second double bonded carbon as 6, which would be incorrect since double bond carbon atoms are assigned the smallest possible locator numbers unless there i...

Nikhil_Madan_3C

Page 52 of the course reader says that at 25 degrees celsius (2.303RT)/F = 0.0592 V
However, when I do the calculation, (2.303(8.314 j*k^-1*mol^-1)(298 K))/(96,4853 C*mol^-1), I get 0.0059 V.
Is there and issue with the calculation or units that is resulting in a different voltage?

Nikhil_Madan_3C

It is multiplied by 1/2 because the questions says that Ron "realizes that half of his 255 g forgetfulness potion has boiled away. Therefore, you would multiply the mass by 1/2 since only half of it was converted into vapor.

Nikhil_Madan_3C

In a neuron (a nerve cell), the concentration of K ions inside the cell is about 20–30 times as great as that outside. What potential difference between the inside and the outside of the cell would you expect to measure if the difference is due only to the imbalance of potassium ions? The solution s...

Nikhil_Madan_3C

The practice problems deal with pairs of electrons being transferred so that's why mostly full arrows are used. Each bond consists of two shared electrons. The chlorine is more electronegative than the carbon so you can think about it like the chlorine pulling the electrons towards itself from the b...

Nikhil_Madan_3C

I thought when ∆Gr°< 0, then the reaction is exergonic and favorable so K > 1 and when ∆Gr°> 0, the endergonic reaction is unfavorable so K < 1. So when part c asks which profiles would have K > 1, I thought they would be 1 and 2 since they both of their ∆Gr°are less than zero. However,the solution ...

Nikhil_Madan_3C

To prepare a 15-kg dog for surgery, 150 mg of the anesthetic phenobarbitol is administered intravenously. The reaction in which the anesthetic is metabolized (decomposed in the body) is first order in phenobarbitol and has a half-life of 4.5 h. After about 2 h, the drug begins to lose its effect. Ho...

Nikhil_Madan_3C

Determine the rate constant for each of the following first-order reactions, in each case expressed for the rate of loss of A: (a) A --> B, given that the concentration of A decreases to one-half its initial value in 1000. s; (b) A --> B, given that the concentration of A decreases from 0.67 mol L^-...

Nikhil_Madan_3C

Nikhil_Madan_3C

The midterm consists of material from the course reader to page 54, which covers thermodynamics and electrochemistry. Doing the homework problems and then doing the practice midterms would be good preparation for the midterm. Good luck!

Nikhil_Madan_3C

Yes, you are correct. The enthalpy of vaporization is positive because it represents the energy that must be added to the liquid substance to transform a quantity of that substance into gas.

Nikhil_Madan_3C

You should use C, it is a typo in the solutions manual.
https://lavelle.chem.ucla.edu/wp-conten ... rs_6Ed.pdf

Nikhil_Madan_3C

Use the information in Tables 8.3, 8.6, and 8.7 to estimate the enthalpy of formation of each of the following compounds in the liquid state. The standard enthalpy of sublimation of carbon is 717 kJ·mol 1. (a) H2O; (b) methanol, CH3OH; (c) benzene, C6H6 (without resonance); (d) benzene, C6H6 (with r...

Nikhil_Madan_3C

The gas constant should be given in different units (J*K^-1*mol^-1, L*atm*K^-1*mol^-1, L*atm*K^-1*mol^-1, L*bar*K^-1*mol^-1, L*Torr*K^-1*mol^-1).

Nikhil_Madan_3C

If you're not part of the solution, you're part of the precipitate

Nikhil_Madan_3C

The problem gives you the ΔHc for C2H2, C2H6, and H2. ΔHc is the enthalpy for the combustion of that compound. So you would get the three equations by writing the combustion equation for all three of the compounds and balancing them. For example, for C2H2, Combustion means that O2 is a reactant and ...

Nikhil_Madan_3C

Which of the following indicators could you use for a titration of 0.20 M CH3COOH with 0.20 M NaOH. Explain your selection and justify your answer with detailed calculations. The solution for this question states that because the both acid and base have identical concentrations and at the stoichiome...

Nikhil_Madan_3C

If an acid is considered strong, that means it completely ionizes so we can say that the concentration of the acid equals the concentration of Hydronium ions. You would not be able to know if if the acid or base completely ionizes unless you know it is strong.

Nikhil_Madan_3C

According to the course reader if a reaction requires heat (endothermic) while forming a product then heating will favor P formation. Does this mean that the equilibria will shift to the right because there would be more products at equilibrium or that the equilibria would shift to the left because ...

Nikhil_Madan_3C

For our purposes, oxalato should have a charge of 2- as shown in the course reader.

Nikhil_Madan_3C

NH₄[PtCl₃(NH₃)]
The name of this ammoniumamminetrichloroplatinate (II)
I was wondering why the charge of Platinum would be II and why metal is written in terms of an anion as platinate instead of platinum.

Nikhil_Madan_3C

To find out if a material is paramagnetic or diamagnetic, you need to know whether it has unpaired electrons. So yes, you would have to use the molecular orbital energy diagram to find out whether it has unpaired electrons or not. If it does have unpaired electrons, then it is diamagnetic and if it ...

Nikhil_Madan_3C

I was wondering which rule takes precedence over the other in some cases. For example, If we were following the octet tule PO4^3- will have lone pairs around each oxygen atom with all single bonds between the oxygen atoms and phosphorus. But according to the formal charges, the more stable lewis str...

Nikhil_Madan_3C

The electron configuration for Niobium is [Kr] 4d^4 5s^1. I was wondering why this is an exception and not [Kr] 4d^3 5s^2.

Nikhil_Madan_3C

They do have 8 valence electrons. However, they are not as reactive as other atoms because they already have an octet.

Nikhil_Madan_3C

If H2O is water, and H2O2 is hydrogen peroxide, then what is H2O4?

Drinking.

Nikhil_Madan_3C

Thanks!

Nikhil_Madan_3C

The change in energy would be negative because the electron is losing energy when it goes from a higher shell to a lower shell.

Nikhil_Madan_3C

If a photon has a wavelength of 5.50 x10^2 nm what is its energy? 5.50 x 10^2 nm = 5.50 x 10^-7 m E = hv = (hc)/λ = ((6.626 x 10^-34 Js) (3.00 x 10^8 m/s))/(5.50 x 10^-7 m) = 3.61 x 10^19 J The answer says 3.6 x 10^-19 J, but the least amount of sig figs in the equation is 3, so I got 3.61 x 10^19 J...

Nikhil_Madan_3C

Thank you!

Nikhil_Madan_3C

1.37 Protons and neutrons have nearly the same mass. How different are their wavelengths? Calculate the wavelength of each particle when traveling at 2.75 x 10^5 m/s in a particle accelerator and report the difference as a percentage of the wavelength of the neutron. Since the mass of protons and ne...

Nikhil_Madan_3C

I believe that molecular spectroscopy can be used to identify molecules because they exhibit characteristic absorption spectrums similar to how atoms do. Even though there many possible molecules, they are all composed of different elements and different numbers of those elements so molecules will a...

Nikhil_Madan_3C

OH- is a hydroxide ion, which has a charge of 1-. There are some ions that you have to memorize the charges of. The charges of the single atoms such as Na and O, you can find from the periodic table. This site highlights the trend in the periodic table you can use to find the ionic charge of atoms. ...

Nikhil_Madan_3C

What they mean by "sulfide of this metal" is the metal sulfide. So you have to write the formula of the metal sulfide. In order to do that you need to know the charge of the unknown metal atom. You can find that by looking at the given formula M(OH)2. Since the formula has the hydroxide io...

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