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Chemistry HL/SL help


Hedron123

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  • 2 months later...

I have a question on the topic of the flame test/AES (atomic emission spectroscopy). In the lab report, I was asked to give wavelengths that are responsible for the colors in the flames after putting different elements in the Bunsen burner. Are those wavelengths equal to the wavelengths of intense lines of elements? Here I found them: https://books.google.pl/books?hl=pl&lr=&id=5VApgsCUL_IC&oi=fnd&pg=PA221&dq=atomic+emission+spectroscopy&ots=sr-bx4Gxz7&sig=8AWor1kGLRiDVQdHm1IrIL-QKKE&redir_esc=y#v=onepage&q=atomic%20emission%20spectroscopy&f=false (p. 225). I know that some of them are for sure (for example for Na - 589 nm), but some of the intense lines are in the not visible spectrum... 

 

Will be grateful for a quick answer :)

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  • 1 month later...

Hey guys

 

Im doing some mole concept questions and I’m getting equations wherein we have to divide 7.75 by 6.022 and .452(181.19 g)

So I’m just wondering whether these hard questions would come in Paper I, does IB expect us to do this without a GDC??

Im doing some mole concept questions and I’m getting equations wherein we have to divide 7.75 by 6.022 and .452(181.19 g)

So I’m just wondering whether these hard questions would come in Paper I, does IB expect us to do this without a GDC??
 
 
Im in Chem HL btw
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Hey guys

 

Im doing some mole concept questions and I’m getting equations wherein we have to divide 7.75 by 6.022 and .452(181.19 g)

So I’m just wondering whether these hard questions would come in Paper I, does IB expect us to do this without a GDC??

Im doing some mole concept questions and I’m getting equations wherein we have to divide 7.75 by 6.022 and .452(181.19 g)

So I’m just wondering whether these hard questions would come in Paper I, does IB expect us to do this without a GDC??
 
 
Im in Chem HL btw

 

 

You should be given questions where you have to multiply or divide Avogadro's constant by a whole number. 

Example:

Determine the number of H atoms in one mole of CH3COOH.

One molecule of CH3COOH has 4 H atoms.

One mole of CH3COOH has 4 x 6.02 x 1023 H atoms

= 2.41 x 1024 H atoms

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  • 4 weeks later...

I have a question for 'acid  and  base'.  

 

3. when hydrochloric acid is added to a solution of sodium hydrogencarbonate, NaHCO3 carbon dioxide is evolved.se if it i

 

b)1, deduce the formula of the conjugate base if it is behaving as an acid.

   2, deduce  the formula of the conjugate acid if it is behaving as an base.

 

Answer

1.CO3^2-

2, H2CO3 or H2O / H2O

 

Could anyone explain this answer?

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I have a question for 'acid  and  base'.  

 

3. when hydrochloric acid is added to a solution of sodium hydrogencarbonate, NaHCO3 carbon dioxide is evolved.se if it i

 

b)1, deduce the formula of the conjugate base if it is behaving as an acid.

   2, deduce  the formula of the conjugate acid if it is behaving as an base.

 

Answer

1.CO3^2-

2, H2CO3 or H2O / H2O

 

Could anyone explain this answer?

Ok so you look at net ionic equations. for the NaHCO3, ignore the Na and look at it as HCO3-. The conjugate base for it would be CO32- because if it's an acid, it's a proton donor, so the H+ is donated and you are left with CO32-

 

For the second one: So if the HCO3- is the base, then it is a proton acceptor, so it gets another H+. Therefore, it becomes H2CO3

 

I'm sorry if this is a crappy explanation by the way :P 

Edited by ShootingStar16
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  • 1 year later...
1 hour ago, Julieta Tonda said:

Hi! I was wondering if someone could explain me radioactivity, because I need to do a lab report and I need to explain what it is, but I'm confused...I really appreciate if someone coul explain me

Thanks!

Radioactivity is more of a nuclear physics phenomena. Generally, particle or particles, such as electrons and alpha particles, are emitted from the atom to achieve a nucleus more stable (lower in energy). This is often due to the weak force overtakes the strong force in nuclei with high neutron-proton ratio. 

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  • 2 months later...
On 10/24/2010 at 11:13 PM, Hedron123 said:

Hey people, I've been away for a while. The good thing is that I'm back and I'm willing to help any Chemistry student with their problems or doubts. I'll be glad to help you with questions regarding lab reports, designs, theory or even on how to approach the actual paper.

I hope to be useful.

Thanks in advance.

Regards

hey hedron,

i really need help understanding chemistry because the teacher teaching at my school is not good at all. firstly i wanna pursue a career in biomedical research and a lot of people have told me to take chemistry at hl but i have taken it at sl because i find it hard especially due to the teacher. so if  u could help me in deciding and learning i would be of a great help.

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  • 2 months later...
  • 2 years later...

Hello so I am struggling to find ideas for experiments for my chemistry IA. 

I definitely want to do an experiment with medicines because it is related to my future job.

However, aspirin hydrolysis is done by another student so it is not preferred to do it.

Also, titration and the synthesis of a drug take too much time.

I am desperate for someone who can suggest me an experiment. 

Yours sincerely,

Sarah

 

 

 

 

 

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On 10/25/2010 at 1:43 AM, Hedron123 said:

Hey people, I've been away for a while. The good thing is that I'm back and I'm willing to help any Chemistry student with their problems or doubts. I'll be glad to help you with questions regarding lab reports, designs, theory or even on how to approach the actual paper.

I hope to be useful.

Thanks in advance.

Regards

Hi there! For my ia lab report, im not sure if I should do an experiment based on finding the activation energy of catalytic decomposition of hydrogen peroxide with catalase compared to another catalyst or if I should do an experiment based on finding the biodegradable oxygen demand of the decomposition of a certain bacteria (which I haven't fully got an idea of)?

if you can give my some suggestions that would be of great help!!

Thank you!!

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  • 2 months later...

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