CHEMISTRY COMMUNITY

Annie Ye

You would only look at bond lengths if it was with binary acids. For oxoacids, you would look at the electronegativity.

Annie Ye

I also don't have a mnemonic but quizlet is actually very helpful! When memorizing CN, NC, SCN, and NCS, I realized that the complementing compound beginning with N will always begin with iso-. For example, CN is cyanate, and NC is isocyanate. SCN is thiocyanate, and NCS is isothiocyanate. Hope thi...

Annie Ye

how do you compare between an oxoacid and a binary acid?

Annie Ye

Yes the abbrevations are fine. e.g. en, dien, edta

Annie Ye

Cisplatin is an example of a chemoterapy drug. It binds to the Guanine in DNA and stops replication. Transplatin is not effective because it only forms one bond with DNA.

Annie Ye

how does carbon monoxide poisoning affect hemoglobin?

Annie Ye

You have to have 50 posts by the end of the quarter.

Annie Ye

hemoglobin is made up of 4 myoglobins. each myoglobin can attach to O2.

Annie Ye

pH= -log(H+) you can also find pH from the equation 14= pOH+ pH if you were given the pOH.

Annie Ye

Cynthia Rodas 4H wrote:Hydrogen bonds are stronger than dipole-dipole. The strength for intermolecular forces arranged from lowest to highest is London forces, dipole-dipole, H-bonding, and ion-dipole.

Why are hydrogen bonds stronger than dipole dipole?

Annie Ye

Ligands are electron pair donors and they are Lewis bases. They donate electrons to the Lewis acid.

Annie Ye

Cisplatin stops the DNA polymerase from replicating the DNA. Transplatin is weak because the DNA polymerase can knock it off.

Annie Ye

Dear Dr. Lavelle, Thank you for putting in so much effort in helping all of us succeed. I learned a lot in your class and I actually find chemistry interesting now. My experience was chemistry in high school was not the best but this class has definitely changed my mind. Thank you for all the review...

Annie Ye

Elements in 3p or higher have the octet exception because of the d orbital.

Annie Ye

No, there has to be at least 3 atoms for resonance.

Annie Ye

can bases be polyprotic? If so, what are the chemical equations representing that?

Annie Ye

hydrogen bonding is an intermolecular force between H- N, O, F

Annie Ye

Yes because the shape can determine if the dipole moments cancel out.

Annie Ye

we must have 50 posts by the end of the quarter.

Annie Ye

Cindy Adiwidjaja 1E wrote:I saw from previous years' posts that Lavelle also adds 10 points to every one's score out of 500. I do not know if this is still true, but this popped up a lot in Chemistry Community.

That would be great if he does curve the points!

Annie Ye

When the spin is up, the ms is +1/2 and when the spin is down it is -1/2

Annie Ye

LDF exists between all molecules because electrons move randomly.

Annie Ye

You would count the lone pairs as electron density. Bonds and lone pairs count in hybridization.

Annie Ye

if there is a curve, will the curve be adjusted for only those who received 50% to get a C- or everyone's grades be curved?

Annie Ye

You would use bis tris tetrakis for polydentate ligands for example (en)2 would be bisen.

Annie Ye

How do I count hydrogen bonds?

Annie Ye

Are hydrogen bonds stronger than dipole dipole?

Annie Ye

Electronegativity causes a bond to be stronger

Annie Ye

Sigma bonds are stronger because the orbitals overlap whereas for pi bonds, the orbitals can break when the molecule rotates.

Annie Ye

The trend of acidity increases from left to right across the periodic table but it decreases going from top to bottom.

Annie Ye

In diffraction, light acts like a wave through the 2 slits because it causes diffraction patterns. The photoelectric effect would show light that acts like particles.

Annie Ye

It means that the solution is very acidic.

Annie Ye

Using clean coal instead of dirty coal can also reduce acid rain. It reduces the amount of sulfur produced.

Annie Ye

H2SO4 would be polyprotic because it can donate more than one proton.

Annie Ye

Yes, for pH you count after the decimal.

Annie Ye

examples of some weak bases? How do we tell which base is weaker?

Annie Ye

What should I focus on when studying acids and bases? Are doing all the homework problems helpful in preparing me for the final?

Annie Ye

In determining the strength of the acid when bond lengths aren't applicable, then you would look at the electronegativity. CH3 or NH2?

Annie Ye

Yes polydentates are considered to be chelating ligands. An example would be the porphyrin ligand.

Annie Ye

How do I know if something is a Bronsted base or acid? How do they compare to Lewis base and acids?

Annie Ye

What are some examples of some polyprotic bases? How can they gain protons? What are the chemical reactions that show it?

Annie Ye

How to determine if whether something is polyprotic? Is NH4 polyprotic?

Annie Ye

Does anyone have a mnemonic to help memorize the ligands?

Annie Ye

Why is HF a weaker acid than HI?

Annie Ye

What do we use Ka and Pka for? What do they represent?

Annie Ye

Alkaline means that it is basic.

Annie Ye

How do we determine which acid is stronger given the chemical formula? Is there a periodic trend?

Annie Ye

Lewis acid is the electron acceptor while the Lewis base is an electron donor. The Lewis base could be the ligands surrounding the Lewis acid.

Annie Ye

How do we determine the hybridization of pi bonds?

Annie Ye

How do we know if a chemical formula is more polyprotic? How do we determine the strength?

Annie Ye

How do we approach titration problems on the final? I am unsure of how the questions would be phrased on the test regarding titrations. What would we need to study regarding titrations?

Annie Ye

What are the chemical reactions that produce acid rain? How is acid rain reduced?

Annie Ye

Are conjugate bases and acids always to the right of the chemical equation (products)?
Do conjugate bases and acids only form from bronstead acids and bases?

Annie Ye

How do we determine if a compound is amphoteric if we are given the chemical formula?

Annie Ye

How do we name coordination compounds? Does the ligand always go first when naming the formula?

Annie Ye

Suggest an explanation for the different strengths of (a) ace- tic acid and trichloroacetic acid; (b) acetic acid and formic acid.

Annie Ye

Decide which acid in each of the following pairs is the
stronger and explain why: (a) HF or HCl; (b) HClO or HClO2; (c) HBrO2 or HClO2; (d) HClO4 or H3PO4; (e) HNO3 or HNO2; (f) H2CO3 or H2GeO3.

Annie Ye

Which is the stronger base, the hypobromite ion, BrO2, or
morphine, C17H19O3N? Justify your answer.

Annie Ye

The pH of several solutions was measured in the research laboratories of a food company; convert each of the following pH values into the molar concentration of H3O1 ions: (a) 3.3 (the pH of sour orange juice); (b) 6.7 (the pH of a saliva sample); (c) 4.4 (the pH of beer); (d) 5.3 (the pH of a coffe...

Annie Ye

Write the chemical equations of the two proton transfer equilibria that demonstrate the amphiprotic character of (a) HCO32; (b) HPO422. Identify the conjugate acid–base pairs in each case.

Annie Ye

Identify (a) the Brønsted acid and base in the following reaction, and (b) the conjugate base and acid formed:
HNO3(aq) 1 HPO422(aq) ¡ NO32(aq) 1 H2PO42(aq)

Annie Ye

Predict the shapes and estimate the bond angles of (a) the thiosulfate ion, S2O322; (b) (CH3)2Be; (c) BH22; (d) SnCl2.

Annie Ye

Predict the bond angles at the central atom of the following molecules and ions: (a) ozone, O3; (b) azide ion, N32; (c) cyanate ion, CNO2; (d) hydronium ion, H3O1.

Annie Ye

Draw the Lewis structure, VSEPR formula, molecular shape, and bond angles for each of the following species: (a) I32; (b) POCl3; (c) IO32; (d) N2O.

Annie Ye

(a) What is the shape of an ICl3 molecule (iodine is the cen- tral atom)? (b) What value is expected for the ClICl bond angle?

Annie Ye

a) What is the shape of a thionyl chloride molecule, SOCl2? Sulfur is the central atom. (b) How many different OSCl bond angles are there in this molecule? (c) What values are expected for the OSCl and ClSCl bond angles?

Annie Ye

Compounds having bonds with a high covalent character tend to be less soluble in water than similar compounds that have low covalent character. Use electronegativities to predict which of the following compounds is the more soluble in water: (a) AlCl3 or KCl; (b) MgO or BaO.

Annie Ye

For each pair, determine which compound has bonds with greater ionic character: (a) HCl or HI; (b) CH4 or CF4; (c) CO2 or CS2.

Annie Ye

Which of these compounds has bonds that are primarily ionic? (a) BBr3; (b) BaBr2; (c) BeBr2.

Annie Ye

Place the following elements in order of increasing electro-
negativity: antimony, tin, selenium, and indium.

Annie Ye

Identify the hybrid orbitals used by the phosphorus atom in each of the following species: (a) PCl41; (b) PCl62; (c) PCl5; (d) PCl3.

Annie Ye

Identify the hybrid orbitals used by the atom in boldface red type in each of the following species: (a) BF3; (b) AsF3; (c) BrF3; (d) SeF31.

Annie Ye

State the hybridization of the atom in boldface red type in each of the following molecules and ions: (a) BeCl2; (b) BH3; (c) BH42; (d) SiF4.

Annie Ye

How many s-bonds and how many p-bonds are there in (a) H2S and (b) SO2?

Annie Ye

State the relative orientations of each of the following hybrid
orbitals: (a) sp3; (b) sp; (c) sp3d2; (d) sp2.

Annie Ye

Explain the difference in the boiling points of AsF3 (63 8C) and AsF5 (253 8C).

Annie Ye

Which of the following molecules are likely to form hydro- gen bonds: (a) PH3; (b) HBr; (c) C2H4; (d) HNO2?

Annie Ye

Suggest, giving reasons, which substance in each of the fol- lowing pairs is likely to have the higher normal melting point (Lewis structures may help your arguments): (a) HCl or NaCl; (b) C2H5OC2H5 (diethyl ether) or C4H9OH (butanol); (c) CHI3 or CHF3; (d) C2H4 or CH3OH.

Annie Ye

For which of the following molecules will dipole–dipole inter- actions be important: (a) CH4; (b) CH3Cl; (c) CH2Cl2; (d) CHCl3; (e) CCl4?

Annie Ye

Identify the types of attractive intermolecular interactions that might arise between molecules of each of the following sub- stances: (a) NH2OH; (b) CBr4; (c) H2SeO4; (d) SO2.

Annie Ye

Which M21 ions (where M is a metal) are predicted to have the following ground-state electron configurations: (a) [Ar]3d7; (b) [Ar]3d6; (c) [Kr]4d4; (d) [Kr]4d3?

Annie Ye

Give the ground-state electron configuration expected for
each of the following ions: (a) Cu1; (b) Bi31; (c) Ga31; (d) Tl31.

Annie Ye

Give the ground-state electron configuration expected for each of the following ions: (a) S22; (b) As31; (c) Ru31; (d) Ge21.

Annie Ye

Give the number of valence electrons (including d electrons)
for each of the following elements: (a) Sb; (b) Si; (c) Mn; (d) B.

Annie Ye

In each second, a certain lamp produces 2.4 3 1021 photons with a wavelength of 633 nm. How much power (in watts) is pro- duced as radiation at this wavelength (1W 5 1 J?s21)?

Annie Ye

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.

Annie Ye

2C.7 Determine the numbers of electron pairs (both bonding and lone pairs) on the iodine atom in (a) ICl21; (b) ICl42; (c) ICl3; (d) ICl5.

Annie Ye

2C.1 Which of the following species are radicals? (a) NO22; (b) CH3;
(c) OH; (d) CH2O.

Annie Ye

2A.23 On the basis of the expected charges on the monatomic ions, give the chemical formula of each of the following compounds: (a) magnesium arsenide; (b) indium(III) sulfide; (c) aluminum hydride; (d) hydrogen telluride; (e) bismuth(III) fluoride.

Annie Ye

2A.21 Give the ground-state electron configuration and number of unpaired electrons expected for each of the following ions: (a) Ca21; (b) In1; (c) Te22; (d) Ag1.

Annie Ye

For each of the following ground-state atoms, predict the type of orbital (1s, 2p, 3d, 4f, etc.) from which an electron will be removed to form the 11 ion: (a) Ge; (b) Mn; (c) Ba

Annie Ye

Which of the following statements are true for many electron atoms? If false, explain why. (a) The effective nuclear charge Zeffe is independent of the number of electrons present in an atom. (b) Electrons in an s-orbital are more effective than those in other orbitals at shielding other electrons f...

Annie Ye

Why are s-block metals typically more reactive than p-block metals?

Annie Ye

Place the following ions in order of increasing ionic radius: S22, Cl2, P32.

Annie Ye

For each orbital listed in Exercise 1D.15, give the possible values of the magnetic quantum number.

Annie Ye

Which of the following increase when an electron in a lith- ium atom undergoes a transition from the 1s-orbital to a 2p-orbital? (a) Energy of the electron. (b) Value of n. (c) Value of l. (d) Radius of the atom. Which answers would be different for a hydrogen atom and in what way would they be diff...

Annie Ye

In the spectrum of atomic hydrogen, several lines are gen- erally classified together as belonging to a series (for example, Balmer series or Lyman series, as shown in Fig. 1A.10). What is common to the lines within a series that makes grouping them together logical?

Annie Ye

What is the minimum uncertainty in the speed of an electron confined within a lead atom of diameter 350 pm? Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom.

Annie Ye

A lamp rated at 32 W (1 W 5 1 J?s21) emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?

Annie Ye

Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning. (a) The speed of the radiation decreases. (b) The wavelength of the radiation decreases. (c) The extent of the change in the electrical field at a given point decreases. (d) The energy o...

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