CHEMISTRY COMMUNITY

NabilaNizam-1K

I think you are trying to calculate the strength of the same type of acid (eg: HCl) before and after dilution. Since pH value is affected by the [H⁺], calculating the concentration of H⁺ in both solutions can give you the pH value by using

pH = -log[H⁺]

NabilaNizam-1K

Since there is a large number of ligands that form coordination compounds with metallic atoms, do we have to memorize the charges of these ligands or is it more beneficial to determine the charge using Lewis structure?

NabilaNizam-1K

It is important to remember that the sigma bond will always form first, followed by the pi bonds. In the formation of multiple bonds, there will always be ONE sigma bond followed by 1 or 2 pi bonds.

NabilaNizam-1K

Do we only classify certain molecules as ligands when it is involved in the formation of an organometallic complex?

NabilaNizam-1K

A sigma bond will always be formed first during the formation of a double bond so a double bond with 2 pi bonds is highly unlikely.

NabilaNizam-1K

Hi Adrienne,

I think instead of unfilled sp3 orbitals, it should be unpaired electron in sp3 orbitals that form σ-bonds since empty orbitals are not able to form any bonds with other atoms

NabilaNizam-1K

Ionic compounds can be made up of covalent bonds, and will only form ionic bonds when the compounds are bonded to another ionic compound.

NabilaNizam-1K

Does this mean if the compound is made up of group 1 or 2 elements and the FONCl elements, the metal elements will always be the central element?

NabilaNizam-1K

Compounds with covalent bond do not dissolve but dissolve in other organic solvents. Ionic compounds dissolve in water as the ions dissociate in the presence of H+ and OH- ions in water

NabilaNizam-1K

Polarizing power refers to the ability of a cation to distort the electron cloud of the anion in an ionic compound. The electron cloud of an anion is pulled towards the cation when it is distorted, giving the ionic bond a covalent character. If the polarization is quite small, an ionic bond is forme...

NabilaNizam-1K

Does the formal charge of the central atom affect the overall charge of the molecule?

NabilaNizam-1K

In order to determine the strength (bond strength) of an acid, it depends on the size of the 'A' atom: the smaller the 'A' atom, the stronger the H-A bond. When going down a row in the Periodic Table, the atoms get larger so the strength of the bonds get weaker, which means the acids get stronger. F...

NabilaNizam-1K

Anions: when an atom gains electrons and form a negatively charged ion due to the increased number of electron
Cations: when an atom loses electrons and form a positively charged ion due to the decreased number of electron

This is basically how I remember it so I hope it helps!

NabilaNizam-1K

Since the first four elements will not achieve octet, is there a special term for the condition when these elements achieve stable state and all the orbitals are filled?

NabilaNizam-1K

Maldonado3K wrote:Hello there, I am overthinking everything.. but just to confirm.. our midterm is taking place in CS50 correct? Thanks!

It depends on your last name
A-F at CS24
G-N at Franz 1178
O-Z at CS76

Hope this helps!

NabilaNizam-1K

hi can you clarify which question 16 because I would love to help!

NabilaNizam-1K

During the formation of a cation, electrons are lost from their shells and since the radius is directly affected by the number of shells, this causes the ion to possess less number of shells than their parent atom, hence they are smaller. Meanwhile, during the formation of an anion, electrons are ga...

NabilaNizam-1K

Based on the calculations, we can find the masses of the products, Fe and Al_2O_3 which are 4.907g and 4.4814 g respectively. Therefore, the mass of excess reactant leftover can be calculated by subtracting the total mass of products from the initial total mass of reactants. Mass of excess reactants...

NabilaNizam-1K

Answer: $3Cu + 8HNO_3 \rightarrow 3Cu(NO_3)_2 + 2NO +4H_2O$

Usually, for balancing equation questions, I try balancing the least abundant element first which is Cu in this case. Hope this helps!

NabilaNizam-1K

I understand that we can use the Rydberg equation to calculate the energy change when electrons are excited from one energy level to another. But what should we do when the values of n are not given? Do we use the Lyman and Balmer series value of n1 as the original value of n?

NabilaNizam-1K

Cu + 4HNO3 --> Cu(NO3)2 + 2NO + 2 H2O

NabilaNizam-1K

S, p, d and f are orbitals for the electrons. Electrons in s orbital has lower energy as it is the smallest orbital and this the energy of the electrons increases when it is in larger orbitals. Size of orbital: s<p<d<f.

NabilaNizam-1K

What affects the threshold energy of a photon?

NabilaNizam-1K

If you are calculating the kinetic energy of the ejected electron, you can use the equation $E= \frac{1}{2} mv^2$
where m=mass of an electron and v=velocity of the electron after it's ejected

NabilaNizam-1K

I think it also helps if we know the order of frequency of the electromagnetic waves, which is the inverse of the wavelength order.

NabilaNizam-1K

Do we have to study the experiment in detail or do we just have to know the concepts and result of the experiment?

NabilaNizam-1K

Hello, I'm having some difficulty determining when to use the M(initial) x V(initial) = M(final) x V(final) equation in problems. Is there any way to know to use this equation in a type of problem? What kind of problems is it used for? Thanks! You can use this equation to find either molarity/conce...

NabilaNizam-1K

I think the direction of the waves can be interchangeable as long as they are drawn perpendicular to each other.

NabilaNizam-1K

In case of calculations that require the usage of values from the periodic table, are we supposed to use the exact value stated or should we round it up?

NabilaNizam-1K

I am wondering how many sig figs are we supposed to round off our answer to after getting the value from a calculator?

CHEMISTRY COMMUNITY

Search found 30 matches

Re: Calculating the difference between two pH values

Charge of ligands

Re: How to identify pi and sigma bonds

Re: Define Ligands?

Re: Double bond with 2 pi bonds?

Re: sp^3 orbitals

Re: 3.35

Re: Finding the central element on the Lewis structure

Re: Solubility

Re: Defining "Distortion"

Re: formal charge on central atom

Re: Lewis Acids and Bases

Re: Difference between anions and cations?

Re: Octet

Re: Midterm [ENDORSED]

Re: q16

Re: Ionic radius trend

Re: Homework M12

Re: Test 1 Q3

Energy difference in excited electrons

Re: balancing chemical reactions

Re: higher energy/ lower energy

Re: Threshold Energy [ENDORSED]

Re: Post-Assessment #31 [ENDORSED]

Re: Wavelengths

Re: Geiger -Marsden experiment [ENDORSED]

Re: When to use MiVi=MfVf

Re: Electromagnetic Field [ENDORSED]

Re: Sig Figs

Re: All students read this sig fig post [ENDORSED]