CHEMISTRY COMMUNITY

derinceltik1K

The UAs mentioned that it would be helpful to know the list of most common strong acids and bases, so when you see an ion you can tell if it came from a strong acid or not, etc.

derinceltik1K

Cis means that the function groups are on the same sides.
Trans means they are on the opposite of each other.
We learned about cis and trans platin in class.
Cisplatin is bioactive and is used in chemotherapy. It has 2 Cls on the same side. Those 2Cls can bind to 2 Guanines and block cell division.

derinceltik1K

They do count as 1 region of electron density around the atom.

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A Bronsted Acid is a proton donor, and a bronzed base is a proton acceptor
For Lewis Acids, they accepts electron pairs and lewis bases donate electron pairs.
They are the same thing but expressed through different functions.

derinceltik1K

my TA told us that we should now cis/trans platin (why cis platin is used in chemotherapy, etc.) and the myoglobin- hemoglobin ring (why carbon monoxide is poisonous, etc.) I believe that's all.

derinceltik1K

Yes, for Bronsted Acids and Bases, we talk about the reaction of a molecule in regards to H+.
If a molecule donates H+, that is a Bronsted Acid (proton donor)
If a molecule accepts H+, that is a Bronsted Base (proton acceptor)

derinceltik1K

Acids will give out H+, making them proton donors.
Bases will gain the H+, making them the proton acceptors.

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Stability is achieved by withdrawing electron from the negatively charged atom. In the HCl and HI examples; Between Cl-O, Cl has an inductive effect (same thing as electronegativity), pulling O's electrons thus stabilizing the negatively charged O. With I-O, I does not have as high of an inductive e...

derinceltik1K

They both refer to the same thing. It doesn't matter which one you use.

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Sigma bonds are first to form between atoms. They are formed by atomic orbital overlap and they allow for rotation.

derinceltik1K

Lone pairs do count as 1 area of electron density. So with VSEPR you have to consider them. But while just drawing the lewis structure you don't have the account for the affect of the lone pair on other bonds. You just draw it and place the lone pairs. But for electron geometry, lone pairs will push...

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Boiling means to transform a liquid substance into vapor or gas.
Melting means to transform from a solid state of matter to liquid.

When it comes to measuring IM force strength, they mean the same thing. The higher point means that the molecule has stronger IM forces.

derinceltik1K

There is more, almost direct, orbital contact in Sigma Bonds. Sigma bonds are formed by head-on overlap, whereas Pi bonds form through side ways.

derinceltik1K

There are no equations that you need to know for Test 2. It mostly covers the VSEPR structures and IM forces.

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A strong acid is one that dissolves completely into its ions in water. A weak acid would only partially dissolve. A weak acid would have a higher pH than a strong acid. Strong acids have pHs closer to 0 and less than pH 7.

derinceltik1K

It's definitely important to know the geometric names. They are the whole point with VSEPR. And Dr. Lavelle mentioned certain details that we don't need to know like the diagrams where it shows which part of the molecule is closer and which atoms are in the back . But the shape, name and the angle w...

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The highest boiling point would be of the strongest molecule. Molecule's strength is measured by its intermolecular forces.
Ionic bonded molecules would have the highest boiling point.
London Dispersion forces would be the easiest to break resulting in lowest boiling points.

derinceltik1K

Yes, I think we are expected to know what the geometrical shape is called and its distinctive characteristics like the bond angles.

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you are expected to know the general idea of conversion but there will be a formula sheet given for the exams.

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No we are not expected to know the electronegativities. If we need to use them in a question they would include them in the question as a footnote.

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nitrogen has a half filled 2p orbital. this makes it more symmetrical therefore more stable. it is harder to get the electron form a highly stable atom. Even though application of periodic table trends indicates that Oxygen should have a higher first ionization energy, it is not the case with nitrog...

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you would want the central atom to have the lowest possible formal charge. It is better for outside atoms to carry the charge than the central atom.

derinceltik1K

ionization energy and electronegativity follow the same trend. Going down the periodic table they decrease and going right, they increase.
this makes fluorine the most electronegative atom.
cesium has the lowest ionization energy.

derinceltik1K

when the bonds get shorter they get increasingly stronger. ex: single bonds being longest and weakest, triple bonds being shortest and strongest.

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fluorine is the most electronegative (increases towards right upper corner of periodic table) element making the C-F bond more ionic.

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a) Comment on the relative bond strength and length of the C–O bond in carbon dioxide, CO2, and H, CH3O H.

How would we solve it ?

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a) Which ion has the most polarizing power? Why? Li+ Na+ K+

how would we solve this question?

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n = shell= indicates row and the energy
l = subshell, relates to the shape, can be from n-1
ml = orientation = "s" is sphere etc
ms = electron spin= can be either -1/2 or + 1/2

derinceltik1K

ionic bonds are between a metal and a nonmetal. They occur through electrostatic attraction of the cation metal and anion nonmetal.
Covalent bonds are between nonmetal atoms. It is through electron sharing.

derinceltik1K

you should pick the central atom based on electronegativity. the least electronegative should be in the middle. You can also use ionization energy as an indicator. It should be the lowest as well for the central atom.

derinceltik1K

Why are Copper and Chronium the exceptions when it comes to electron configuration ?

derinceltik1K

Can someone explain this phenomenon and also penetration? I know that they effect the radius but I don' understand how it does not have any correlation with the subshells but it depends on the Principal Quantum Number?

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I know that for "s", the electrons are more likely to be near the nucleus but what is the case for "p" and "d"
Is it more unlikely to find the electrons near the nucleus because of the shape of the subshells? thank you

derinceltik1K

1.31 In a recent suspense film, two secret agents must penetrate a criminal's stronghold monitored by a lithium photomultiplier cell that is continually bathed in light from a laser. If the beam of light is broken, an alarm sounds. The agents want to use a hand- held laser to illuminate the cell whi...

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The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86 (it has since been redefined). What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond (i.e. infrared, ultraviolet, x-ray, etc.)? W...

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Yes there are different versions of the test for each TA's discussion class I believe. Thanks for the answer though.

derinceltik1K

If 3.607 x 10-19 J is required to remove an electron with zero kinetic energy from a metal surface, what would be the longest wavelength light that could do this?

How would we be able to use the J with the equations?

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1B.21 A baseball must weigh between 5.00 and 5.25 ounces (1 ounce 5 28.3 g). What is the wavelength of a 5.15-ounce base- ball thrown at 92 mph?
Which equations to use?

derinceltik1K

There was a question on the video assignment modules about this.
One answer had "photon" and the other one was "particle"
I thought they were interchangeable, but it seems like one is more appropriate than the other in some instances. Can someone explain?

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Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is the kinetic energy of the ejected electron? How would we solve the question? How to convert kJ to use for t...

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If 10.00 g of glucose is initially present and 5.00 g of H2O is formed, how much grams of glucose is left over? How many moles of O2 were initially present? (glucose is 180.156 g/mol) C6H12O6 + 6O2 -> 6CO2 + 6 H2O + ENERGY I missed this question on Test 1. Can someone explain how to solve this probl...

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The velocity of an electron that is emitted from a metallic surface by a photon is 3.6 3 103 km?s2 1. (a) What is the wavelength of the ejected electron? (b) No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50 3 1016 Hz. How much energy is require...

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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. Can someone explain the question? I could not manage to express "uncertainty in the positi...

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4NH3 + 5O2 ->4NO + 6H20

21.4 g NH3 42.5g O2

Calculate the products in grams?

I get 1.26 moles of NH3 and 1.33 mol of O2 but can't get the calculation right afterwards? How would you solve this?

derinceltik1K

For the following reaction, how many grams of AlCl3 would be obtained if 5.43g of aluminum and 7.80g of hydrogen chloride (HCl) was used in the reaction?
Al (s) + HCl (aq) → AlCl3 (aq) + H2 (g)

I keep getting the calculations wrong? can someone explain step by step?

derinceltik1K

What is the mass percent of the elements in Sr(NO2)2 ?

how would you start to solve this question?

derinceltik1K

How detailed does the dimensional analysis have to be?
For example do we need to write the units for every equation to show how they cancel each other out?

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Aluminum metal reacts with chlorine gas to produce aluminum chloride. In one preparation, 255 g of aluminum is placed in a container holding 535 g of chlorine gas. After reaction ceases, it is found that 300. g of aluminum chloride has been produced. c)What is the percentage yield of aluminum chlori...

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"Aspartame, C14H18N2O5, is a solid used as an artificial sweetener. Write the balanced equation for its combustion to carbon dioxide gas, liquid water, and nitrogen gas."

How would this equation be balanced?

derinceltik1K

How would we write the equation for:
Fe2O32's reaction with carbon monoxide?

derinceltik1K

Sodium bromide, NaBr, which is used to produce AgBr for use in photographic film, can itself be prepared as follows... Fe+Br2->FeBr2 FeBr2+ Br2->Fe3Br8 Fe3Br8+ Na2CO3-> NaBr+ CO2+ Fe3O4 What is the mass of iron in kg is needed to produce 2.50 t of NaBr (equations must be first balanced) - I keep get...

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