CHEMISTRY COMMUNITY

Chris Qiu 1H

Hi Haya! The percent composition you can turn into grams turning the percents into decimals and multiplying by 100. Afterwards you would turn all the grams into moles of their respective element. Then you take the smallest mole value and divide it by all of the values. For this problem that would ge...

Chris Qiu 1H

Salts usually dissociate into its two parts in water. Conjugate bases accept Protons and would thus take it from the water making OH ions. OH ions are associated with bases and would thus raise the pH.

Chris Qiu 1H

No, we never got that far.

Chris Qiu 1H

There are three angles you look at when you view t shaped. Without taking into account lone pair repulsion you would have two 90 degree angles and one 180 degree. However the lone pairs will push the two atoms making the top of the T closed towards the third atom. This would mean that the 90 degree ...

Chris Qiu 1H

Pi bonds cant rotate so there will be no double bound ligands.

Chris Qiu 1H

Anything past the third group can have an expanded octet.

Chris Qiu 1H

Lewis acids accept electrons while lewis bases donate electrons. What the acid becomes is the conjugate base in the reaction and what the base becomes is the conjugate acid.

Chris Qiu 1H

Is this question asking about what atom will be the central atom? In that case for BrB there technically isn't a central atom. For PS2 its typical for this case for the element that has only one of it (P in this case) to be the central atom.

Chris Qiu 1H

All atoms that have enough electrons to form triple and double bonds can form them. However, whether they form them or not is dependent on the formal charge of the molecule. (You try to minimize the amount of formal charges that arn't zero)

Chris Qiu 1H

If I recall, the professor told us we would not have to draw vsepr structures (what your talking about), but we would have to know he names of the shapes and the bond angles.

Chris Qiu 1H

You go off of polarzability, if the elements that are bound in one instance have higher polarizability then they will create a stronger bond.

Chris Qiu 1H

High polarizability creates stronger bonds which is why ions with bigger atomic radii (higher polarizability) like Br2 and I2 are not gases

Chris Qiu 1H

This related to cations, Polarizability relates to anions

Chris Qiu 1H

Count how many valence electrons each atom has, add them together taking into account the charge, if that number is odd then it will be a radical.

Chris Qiu 1H

Valence electrons for Cobalt are tricky since it is a transition metal. Writing the shorthand electron configuration for Cobalt ([Ar] 3d7 4s2) there are nine electrons which you actually specified. Thus Cobalt has 9 valence electrons, however the D orbital isn't known to get involved in bonds and li...

Chris Qiu 1H

The expanded octet rule can only apply to elements on the third row of the periodic table or higher due to the presence of the D-orbitals. Florine does not fit those criteria so there is only one option for the extra electrons, placing them on Xenon.

Chris Qiu 1H

you would have to use the reinberg equation with a Balmer series drop (you would know you need to see this since the wavelength is in the visible range which is the balmer series) a balmer series is a drop from n=x to n=2

Chris Qiu 1H

I'd keep 3-4 sig figs just to be safe. Having only one sig fig for a value that wont be a whole number (or a single digit for that manner) doesn't make too much sense.

Chris Qiu 1H

What you wrote says 3p but you asked about 3d in the header so I assume you just miss-typed. We know that the 4s electrons are lost first during ionization which means that they are of a higher energy level than the 3d orbital since the highest electrons are found farthest away from the nucleus, thu...

Chris Qiu 1H

Since it isn't very informative when you just but [Ar] for shorthand it would be safer to just use the noble gas before it and write full orbitals.

Chris Qiu 1H

An orbital is a description of the behavior of an electron as it surrounds the atom. The different types of orbitals (s,p,d,f) exhibit different movements each orbital typically has more energy than the one before it (except for the d orbitals in our respect)

Chris Qiu 1H

This basically means that no electron can have the same spin as any other electron and there are set number of electrons that can be in one orbital.

Chris Qiu 1H

You would use this equation when trying to find the wavelength of a electron that has gone from a high energy level (n2) to a lower energy level (n1). Hope this helps :)

Chris Qiu 1H

When you increase the brightness of a light (that has a frequency that you know can eject the electrons) you are increasing the intensity so there are more photons being emited, thus more electrons will be sent out. For the frequency, there is a underlying frequency a metal requires in order to ejec...

Chris Qiu 1H

Through the equation E^2= [(mc)^2]^2+(pc)^2 when m is equal to zero (since we are taking the momentum of a photon) you are can deduce the function E=pc, which you then can turn into p=E/c. We know the energy of a photon is given by E=(hc)/(wavelength) so when putting that into the equation you get p...

Chris Qiu 1H

For the equation the n1 is meant to represent the lower energy level n of the transition. This is to avoid coming out with a negative value when plugging into the equation.

Chris Qiu 1H

Waves in a series all have similar wavelengths and all transition their electron to the same energy level. i.e the Lyman series are all ultraviolet waves that drop to n1, paschen's are all infrared and fall to n3

Chris Qiu 1H

Grouping these waves into series is helpful because it allows the waves to be categorized by energy levels. i.e Lyman's series are all ultraviolet, Paschen's lie in infrared.

Chris Qiu 1H

For balanced equations where the moles arn't one to one make a conversion like how you would do with grams or liters. Manipulate the ratio, whatever it may be, so that the moles of whichever element you want it the only unit remaining. i.e If you have 1.6 moles of compound X and want to know how muc...

Chris Qiu 1H

You use dimensional analysis whenever you need to change a value from one type of unit (meters) to another unit (kilometers). I find the easiest way to do these calculations is to make sure that after the calculation the only unit(s) that haven't canceled out are your desired units.

Chris Qiu 1H

Typically you use 16 as the mass for oxygen. For this case the difference between 15.999 and 16 is so small it never really matters once you take significant figures into consideration.

CHEMISTRY COMMUNITY

Search found 31 matches

Re: 4.75 [ENDORSED]

Re: salts & conjugate base

Re: Configurations including f-orbitals

Re: T-Shape

Re: Ligand bind to metal

Re: expanded octet

Re: Difference between Lewis and conjugate acids and bases

Re: Highest Ionization Energy

Re: Double/Triple Bonds

Re: HW 4.3 - structure of CH2F2

Re: Bond Strength In Same Group

Re: Does being more polarizable= Being stronger?

Re: polarization power

Re: Radicals [ENDORSED]

Re: Valence Electrons by Group

Re: expanded octet XeF4

Re: Test 2 Question 4

Re: How many significant figures? [ENDORSED]

Re: Energy difference between 4s and 3d

Re: Using shorthand [Ar] [ENDORSED]

Re: The concept of Orbitals

Re: Four Different Quantum Numbers

Re: Rydberg [ENDORSED]

Re: Looking over discussion problems

Re: Question About Photons [ENDORSED]

Re: Question 1.13

Re: 1.11

Re: Solving 1.11 [ENDORSED]

Re: What To Do When Mole Ratios Are Present? [ENDORSED]

Re: Dimensional Analysis Help [ENDORSED]

Re: Which mass of oxygen should be used? [ENDORSED]