CHEMISTRY COMMUNITY

Shreya Tamatam 3B

How do you determine whether an acid is strong or weak?

Shreya Tamatam 3B

How is cisplatin able to stop cell division? What are the mechanics behind that process?

Shreya Tamatam 3B

How do coordinate covalent bonds differ from covalent bonds? Are they the same thing?

Shreya Tamatam 3B

How do you determine what type of forces are present in a molecule? eg. How do you determine if a force is a dipole-dipole interaction versus a Van Der Waals force?

Shreya Tamatam 3B

How do you determine if a molecule is polar or non polar by just looking at its Lewis structure?

Shreya Tamatam 3B

Why is lone-lone pair repulsion strength stronger than lone-bonding pair repulsion strength?

Shreya Tamatam 3B

How and why do lone pairs influence molecular shape?

Shreya Tamatam 3B

How are induced dipoles formed?

Shreya Tamatam 3B

Why is dissociation energy always positive?

Shreya Tamatam 3B

Why do molecules with hydrogen bonds have higher melting and boiling points?

Shreya Tamatam 3B

How can you tell whether a molecule has a tetrahedral structure instead of a see saw structure? Does the number of lone pairs the central atom has have any effect on the molecule's shape?

Shreya Tamatam 3B

How can you tell if a molecule is polar or non polar?

Shreya Tamatam 3B

Does anyone know why H, He, Li, and Be are octet exceptions? What is the explanation behind why they don't conform to the octet rule?

Shreya Tamatam 3B

Can anyone please explain why electronegativity decreases down a group and increases as you move across a period? Thank you!

Shreya Tamatam 3B

The question states, "Select from each of the following pairs of Lewis structures the one that is likely to make the dominant contribution to a resonance hybrid. Explain your selection." For questions such as these, do we just choose the molecule which has formal charges of zero? Would mol...

Shreya Tamatam 3B

You can tell when a compound is a radical if it does not follow the octet rule. For instance, the methyl radical has 7 valence electrons instead of a full octet and is therefore very reactive and unstable. Thus, it will only exist for a short time.

Shreya Tamatam 3B

Hi, just to add on, if you look at the example we did in lecture where we assigned formal charged to a sulfate ion (SO4^2-) we see that two of the oxygen atoms had a -1 charge while all the other atoms had 0 charge. Because two atoms had a -1 charge, the total charge for the molecule was -2.

Shreya Tamatam 3B

No, formal charge only indicates its gain or loss of electrons while forming a covalent bond. So, different atoms in a molecule could still have the same formal charge.

Shreya Tamatam 3B

For atoms like Copper, why does the ground state electron configuration include the element argon? For example, the configuration for Cu+ is [Ar]3d^10. Why is the element argon used and not another element?

Shreya Tamatam 3B

We reviewed high school topics (chemical bonds, ionic bonds, covalent bonds), Lewis structures, and how to draw Lewis Structures of polyatomic species.

Shreya Tamatam 3B

Generally, p-block nonmetals form anions by gaining valence electrons until a noble gas electron configuration is reached. Nonmetals don't form cations because their ionization energies are too high to do so and instead form covalent bonds. Main group metals form cations by losing s and p valence el...

Shreya Tamatam 3B

My TA said that while all equations and constants are provided, we should try and memorize most of them to save time during the test, which will likely take up the entire time period.

Shreya Tamatam 3B

Just to add on, this equation can be used whenever you are given momentum (or mass and velocity), since h and c are constants. Then we can solve for wavelength if the particle has the momentum p and has wavelike properties with a wavelength lambda.

Shreya Tamatam 3B

The question asks "Infrared spectroscopy is an important tool for studying vibrations of molecules. Just as an atom can absorb a photon of suitable energy to move an electron from one electronic state to another, a molecule can absorb a photon of electromagnetic radiation in the infrared region...

Shreya Tamatam 3B

The question asks "A lamp rated at 32 W (1W=1J.s^-1) emits violet light of wavelength 420 nm. How many photons of violet light does the lamp generate in 2 s? How many moles of photons are emitted in that time interval?" To solve this, do we just use the given information and the formula E=...

Shreya Tamatam 3B

The question says "The y-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmeceuticals have an energy of 140.511 keV. Calculate the wavelength of these y-rays." To solve this, do we first convert keV to joules, and then combine the equations E=hv and (lambda...

Shreya Tamatam 3B

The questions says "In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line." How do we begin to solve this question? Sho...

Shreya Tamatam 3B

Just to add on, combustion is a reaction in which oxygen gas (O2) is involved. That's how we know that oxygen gas is a reactant and not a product. Usually the reaction results in CO2 and H2O as a product as well. Since the molecular formula for aspartame is provided, we can write the equation out: C...

Shreya Tamatam 3B

The question provides that a mixture of NaNO3 and Na2SO4 of mass 5.37 g contains 1.61 g of sodium. How do we calculate the percentage mass of NaNO3? Do we find the mass of NaNO3 by finding the mass per mole and then multiplying it by the amount in moles, and then using the mass percentage formula?

Shreya Tamatam 3B

I believe you would round your final answer rather than rounding the numbers in earlier steps. This will make sure your final answer is more accurate. Wait until the final step to round!

CHEMISTRY COMMUNITY

Search found 30 matches

strong vs weak acids

Function of cisplatin

Coordinate covalent bond

Types of intramolecular forces

Polar Molecules

repulsion strength

Lone pairs

Induced dipoles

Dissociation energy

H bonds and melting points

Molecular Shapes

Polar/non polar molecules

Re: List of octect exceptions

electronegativity trends

homework question 3.71 (6th edition)

Re: Radicals

Re: Formal Charge of a compound

Re: Formal Charge

Ground State Electron Configurations

Re: Chemical Bonding

Re: periodic table

Re: Equations

Re: De Broglie

Homework Question 1.55 (6th edition)

HW Question 1.27 (6th edition)

HW Question 1.23 (6th edition)

Homework Question 1.15 (6th edition)

Re: H19 (6th Edition) [ENDORSED]

Homework Question F27 (6th edition)

Re: Sig Figs... when to round?