Physics, Chemistry and Biology: Post your doubts here!

[NOneed2speedd]

why aqueous solution of sodium could not be used for electroplating?

 

[qwertypoiu]

what is meant by Avogadro Constant?

Number of particles (either atoms or molecules) in one mole of any substance is known as the Avogadro's Constant.
Avogadro's constant has the value 6.02214129(27)×1023 mol−1

What does this exactly mean? It means one gram of hydrogen atoms will contain exactly 6.02 x10^23 atoms. 12g of carbon atoms will also contain exactly 6.02x10^23 atoms.

 

[AnonymousX9]

Number of particles (either atoms or molecules) in one mole of any substance is known as the Avogadro's Constant.
Avogadro's constant has the value 6.02214129(27)×1023 mol−1

What does this exactly mean? It means one gram of hydrogen atoms will contain exactly 6.02 x10^23 atoms. 12g of carbon atoms will also contain exactly 6.02x10^23 atoms.

What is one mole then?

 

[AnonymousX9]

Can anyone please tell me the exact definitions for an acid and an alkali?
Also, do we need to know the flame tests?

 

[qwertypoiu]

What is one mole then?

Good question. Definition of mole:
Amount of any substance that contains as many particles (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of pure carbon-12 (12C).

 

[AnonymousX9]

Good question. Definition of mole:
Amount of any substance that contains as many particles (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of pure carbon-12 (12C).

Thanks!

 

[NOneed2speedd]

why aqueous solution of sodium could not be used for electroplating?

If anyone knows please answer. ..

 

[qwertypoiu]

If anyone knows please answer. ..

I'm not too sure...
But it might have to do with Na being too reactive and thus perhaps it cannot be used. Like how H+ ions are more likely to be displaced from solution than Na+ ions due to reactivity series...

 

[Saad the Paki]

Can anyone please tell me the exact definitions for an acid and an alkali?
Also, do we need to know the flame tests?

Acids are proton donors
Alkalis are proton acceptors
the proton here is the H+ ion
No flame tests are not in our syllabus

 

[Saad the Paki]

How to draw ionic diagrams?

https://www.xtremepapers.com/community/attachments/143162419824646390730-jpg.53675/

 

[masterex567]

https://www.xtremepapers.com/community/attachments/143162419824646390730-jpg.53675/

ty so much bro

What's the hardest chem paper 3 you've done?

 

[Tozu Fofo]

Here you find useful notes and tips to help you with your physics exam: https://www.xtremepapers.com/community/threads/please-check-this-link-d.41246/#post-922003

 

[Mr.Physics]

getting cancer is not a social implication

It is counted as an adverse effect .

 

[Saad the Paki]

ty so much bro

What's the hardest chem paper 3 you've done?

Ummmm....
Im not too sure but it was one of the winter papers of 2011

 

[Mr.Physics]

Guyzz what is the direction of electron flow ?? +ve to -ve or -ve to +ve ?

 

[Muaaz Iqbal]

Guyzz what is the direction of electron flow ?? +ve to -ve or -ve to +ve ?

Well That's easy
Electron flow is always from a positive pole to a negative pole. In the case of an electrolytic cell (battery) it is from the cathode (+) to the anode (-)

 

[Shandana khan]

Plzz help friends.... Physics 0652 doubt....can some one plzzz explain how to do this:
Its question no. 9 (c)...

 

[loaie Amgad]

Ummmm....
Im not too sure but it was one of the winter papers of 2011

Hey man .... I have a question
You once told me that we should use a pen for drawing diagrams of bonds in paper 3
But it states clearly on the very first page that we should use a pencil for diagrams
Now What hhhhhh????
Could you please turn out and tell me
Thanks in advance man......

 

[NOneed2speedd]

Hey man .... I have a question
You once told me that we should use a pen for drawing diagrams of bonds in paper 3
But it states clearly on the very first page that we should use a pencil for diagrams
Now What hhhhhh????
Could you please turn out and tell me
Thanks in advance man......

it's not a problem pen or pencil. .. ur answer should be correct

 

[Mr.Physics]

it's not a problem pen or pencil. .. ur answer should be correct

Hahha well said man