CHEMISTRY COMMUNITY

alexis castro 1B

Suppose that 1.436 g of impure sodium hydroxide is dissolved in 300. mL of aqueous solution and that 25.00 mL of this solution is titrated to the stoichiometric point with 34.20 mL of 0.0695 m HCl(aq). What is the percentage purity of the original sample? Was anyone able to figure out this problem? ...

alexis castro 1B

A buffer solution of volume 100.0 mL is 0.100 m CH3COOH(aq) and 0.100 m NaCH3CO2(aq). (a) What are the pH and the pH change resulting from the addition of 10.0 mL of 0.950 m NaOH(aq) to the buffer solution? (b) What are the pH and the pH change resulting from the addition of 20.0 mL of 0.100 m HNO3(...

alexis castro 1B

The percentage deprotonation of benzoic acid in a 0.110 m solution is 2.4%. What is the pH of the solution and the Ka of benzoic acid?

Can someone tell me how they solved this? I am confused about what the solutions manual is doing.

alexis castro 1B

Using data in Tables 12.1 and 12.2, place the following acids in order of increasing strength: HNO2, HClO2, NH3OH, (CH3)2NH2.

Im confused because (CH3)2NH2 isn't given in the tables so how would I find the Ka for it?

alexis castro 1B

Calculate the initial molarity of Ba(OH)2 and the molarities of Ba2, OH, and H3O in an aqueous solution that contains 0.43 g of Ba(OH)2 in 0.100 L of solution.

Can someone tell me how i would set this problem up? i thought i would use ICE box but I am not sure.

alexis castro 1B

604744616 wrote:Does anyone know if any of the end of the section for the chemical equilibrium will be put on the test? I want to know how much of this section of chemical equilibrium will be covered?

all of chapter 11 can be asked about on the test.

alexis castro 1B

I was wondering if we are able to put solids and liquids into an ICE chart. For question 49 the reactant side is only Solids so do i include this in the ICE chart?

alexis castro 1B

Can someone please explain the relation between pressure and volume for chemical equilibrium reactions. I got a little lost in lecture.

alexis castro 1B

for that example because NH2 is in parenthesis next to the C in H2C you can tell that they are saying that the nitrogen will be connected to this carbon.

alexis castro 1B

What -1 anion is isoelectronic with Mg2+? can someone tell me the answer and explain why it is the answer.

alexis castro 1B

Yes when you get a charge of +1 an electron has been lost but most important formal charge tells us which lewis structure is the most stable.

alexis castro 1B

There are no modules for lewis structures.

alexis castro 1B

Can someone explain what makes an element highly polarizable and the what makes other elements not polarizable. I am having a hard time grasping this concept.

alexis castro 1B

4P orbitals: n=4 l=1 ml= -1,0,1 so that means the p orbital has 3 orbitals and each orbital can hold 2 electrons so for the 4P orbital it can have 6 electrons 3D n= 3 l=2 ml= -2, -1, 0, 1, 2 so 5 orbitals each holding 2 electron means a total of 10 electrons 1s n=1 l=0 ml=0 so 1 orbital only 2 elect...

alexis castro 1B

Because n=6 l is able to equal 0, 1, 2, 3, 4, and 5. l in this case equals 3 which refers to f orbital. Theoretically this is a possible orbital but it is just not the ground state of any element on the periodic table.

alexis castro 1B

(b) Determine the mass of CuSO45H2O that must be used to prepare 250 mL of 0.20 m CuSO4(aq). Can someone tell me the steps they took to solve this problem?

alexis castro 1B

Which has the smaller first ionization energy Al or Na. What is a FIRST ionization energy? is it asking for like the original ionization energy before either of these elements start losing or gaining electrons?

alexis castro 1B

Chlorine can exist in both positive and negative oxidation states. What is the maximum (a) positive and (b) negative oxidation number that chlorine can have?

Can someone explain what a positive and negative oxidation state is?

alexis castro 1B

To figure this out you must know what each number of l stands for.
for example:
L=0 its an S orbital
L=1 its a P orbital
L=2 its a D orbital
L=3 its a F orbital

so for n=5 and l=2 it would be 5D

alexis castro 1B

What Lavelle has taught us in class is the empirical version of the Rydberg equation. You can still use the equation lavelle showed us in class to solve the problem but it would just take a few more steps than how the solutions manual showed it with just plugging it all into the original version of ...

alexis castro 1B

It is referring to the excess amount of reactant in the second reaction.

alexis castro 1B

Or is oxygen not in the compound?

alexis castro 1B

I got 1 for C and 4 for H also but what I was confused about is the oxygen. I got 4 for Oxygen but it doesn't seem right.

alexis castro 1B

6.40g of a compound was burned in air and produced 8.80g CO2 and 7.2g of H2O. find the empirical formula of the compound.

Can someone please help. I am so lost on this question.

alexis castro 1B

Ya it is pretty much guess and check but my TA said you shouldn't be multiplying by anything bigger than 4 or 5

alexis castro 1B

you can try and see if SAC has any old test in their test bank

alexis castro 1B

I have heard they are more math based but if you have the course reader it has past exams and test in there so you can get a feel for how his test will be set up.

alexis castro 1B

Can someone explain, in a more simple way than what the book did, how Avogadro found the number 6.022x10^23 and knew it was universal and could be applied to any element to convert it from moles to molecules.

alexis castro 1B

No. because if one side is greater than the other side of the equation then mass is being created or destroyed which is not possible.

alexis castro 1B

2.15 mmol Na+. what does mmol stand for/ mean?

CHEMISTRY COMMUNITY

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