Edexcel CHEMISTRY DOUBTS!!!!

[The Golden Girl =D]

No.......you were not being stupid. Actually I need to apologise since my words were quite offensive

Sorry again

Anyway seems you understood the trend of melting point across period 3 well
That was a 5 star explanation

No worries...............i'll take on the rest

the answer is that HEAVY metals are toxic

[Helium]

anyone mind,

we had a chem practical test,
making a double salt of ammonium sulfate and iron (II) sulfate,

a question said why is it important to add iron filling to sulfuric acid in small portions rather
than all at once?( i think to avoid a vigorous reaction i have other stuff in mind)

we boiled the sulfuric acid and kept adding small portions, anyone one do this?

oh gg long time not seen,

actually been i while i haven't shown

[The Golden Girl =D]

anyone mind,

we had a chem practical test,
making a double salt of ammonium sulfate and iron (II) sulfate,

a question said why is it important to add iron filling to sulfuric acid in small portions rather
than all at once?( i think to avoid a vigorous reaction i have other stuff in mind)

we boiled the sulfuric acid and kept adding small portions, anyone one do this?

oh gg long time not seen,

actually been i while i haven't shown

Actually i don't know the asnwer but perhaps to avoid splashes . idk . wait for D to answer u

Well i had the same exact Q but it was copper carbonate and sulhpiric acid --> Answer is : to prevent frothing.

Helium , Aha ....7esabak ma3ai ba3deen LOL .... It's Okay but u gotta send me a msg to make up for it tho  

[Helium]

Actually i don't know the asnwer but perhaps to avoid splashes . idk . wait for D to answer u

Well i had the same exact Q but it was copper carbonate and sulhpiric acid --> Answer is : to prevent frothing.

Helium , Aha ....7esabak ma3ai ba3deen LOL .... It's Okay but u gotta send me a msg to make up for it tho 

lol

ok thank you ,

I wonder where the teacher got the practical paper from,
it's called ASD1 Preperation of a double salt

[Deadly_king]

the answer is that HEAVY metals are toxic

I think you meant to quote this

could anyone help me in question 2 page 49 of the edexcel A2 book and thanks

part a only

[Deadly_king]

anyone mind,

we had a chem practical test,
making a double salt of ammonium sulfate and iron (II) sulfate,

a question said why is it important to add iron filling to sulfuric acid in small portions rather
than all at once?( i think to avoid a vigorous reaction i have other stuff in mind)

we boiled the sulfuric acid and kept adding small portions, anyone one do this?

oh gg long time not seen,

actually been i while i haven't shown

Hmm.........i was thinking about it

The only reasonable answer that I can find is that upon addition of the iron fillings, gases are emitted. Hence as a precaution add portion by portion so that gases does not affect experimenter. This is frothing 

Moreover, you need to add little by little to make sure that all the iron reacts to form the required salt. You are in some way increasing surface area so that this reaction takes place faster.

Hope I helped

[The Golden Girl =D]

lol

ok thank you ,

I wonder where the teacher got the practical paper from,
it's called ASD1 Preperation of a double salt

Anytime

Teachers get Qs min ilmiree5  , like seriously LOL xD

[Helium]

Hmm.........i was thinking about it

The only reasonable answer that I can find is that upon addition of the iron fillings, gases are emitted. Hence as a precaution add portion by portion so that gases does not affect experimenter. This is frothing 

Moreover, you need to add little by little to make sure that all the iron reacts to form the required salt. You are in some way increasing surface area so that this reaction takes place faster.

Hope I helped

Yes thank you was helpful,

never knew what was frothing , true i never knew hydrogen would choke you so much we  had to open the fan,

some started coughing, lol

thanks DK

[Helium]

Anytime

Teachers get Qs min ilmiree5  , like seriously LOL xD

lol thats sometimes so true, u wonder who wrote the question

[Helium]

Anytime

Teachers get Qs min ilmiree5  , like seriously LOL xD

lol i remembered i funny e-mail on how teachers give thier questions,

The teacher looked into the eyes of his students and said:

My sons know that the doctrines of the scholars of the university
 Questions abound in the development of seven and best known, there

Doctrine zero

 It focuses on the student does not receive more than
 Zero in the exam ..

 Doctrine scary
 
 Students .. And prove this doctrine that Dr.

 Knowledgeable and that he could put tough questions ..

Educational doctrine

 A doctrine which remembers all the
Things that forgot to explain tp studenst during the lecture and then
Established in the form of educational questions, students learn
During the exam ...



it's quite long and translated, i'll message it to u.

google translate not that good

[Deadly_king]

Yes thank you was helpful,

never knew what was frothing , true i never knew hydrogen would choke you so much we  had to open the fan,

some started coughing, lol

thanks DK

No problem

Glad to have been of help

[**RoRo**]

I don't think you need to know that, buddy I had to carry out some research before finding this :

There are 3 properties of a diamond in relation to light :

1. Brilliance : the light reflections caused by the white light that enters the diamond bouncing off its facets inside and exiting the diamond AND also the light that reflects from its surface

2.Fire : the flashes of color, like a rainbow of colors, that you can see in a polished diamond when you move the stone or when you or the light moves. The different colors that make up together the white light that enter the stone are faster or slower than others. When the get reflected inside the gem by its facets and exits the stone, there is a difference in angle between these color rays so you can see separate colors. This creates fire, and it is because of the unique refractive quality diamond has.

3. Scintillation : the flashes of light and the contrasting areas you see when the diamond, the light or the observer moves.

Try not be so curious about things outside the syllabus

Such a compound would be theoretically stable because PCl₃ has a free lone pair of electrons, while BCl₃ is missing a pair of electrons. The lone pair on PCl₃ can coordinate to the empty space on BCl₃, giving all the atoms an octet.

Hence a coordinate covalent bond is formed between the two molecules to form a rather stable compound which is however quite rare

1. Urea is readily available through excrements of most organisms. Hence it is cheaper.
2. The yield is extremely high and it has no side-effects on any plants.

If you have time check these :
http://ezinearticles.com/?Beneficial-Uses-of-the-Urea-Fertilizer&id=5229780

http://www.extension.umn.edu/distribution/cropsystems/dc0636.html

Hope it helps

Thanks a lot!!

[mdwael]

okay so this question keeps making mad when I read it, strongest intermolecular force present in liquid h-cl? ans = induced-dipole-induced dipole -_-
isnt h-cl polar, and if its polar shouldnt it have dipole-dipole intermolecular forces, which are stronger than induced-dipole forces? why does the mark scheme say other wise? past paper is january 2007 unit 1 q 5 a.

everything has been easy so far, except this..

[Deadly_king]

okay so this question keeps making mad when I read it, strongest intermolecular force present in liquid h-cl? ans = induced-dipole-induced dipole -_-
isnt h-cl polar, and if its polar shouldnt it have dipole-dipole intermolecular forces, which are stronger than induced-dipole forces? why does the mark scheme say other wise? past paper is january 2007 unit 1 q 5 a.

everything has been easy so far, except this..

HCl is indeed a polar molecule within which there exist permanent dipole-permanent dipole forces of attraction. These forces occurs between the partially negatively charged chlorine and the partially positively charged hydrogen from another molecule. This is because chlorine is electronegative, hence it attracts the shared pair of electrons towards itself.

Now let's get back to your question :
Q : Name the strongest intermolecular force present in liquid HCl
I would have said permanent dipole - permanent dipole forces of attraction.

I can't explain the reasoning of the marking scheme. I guess there might be a mistake or something like that. I'll advise you to consult a tutor.

[Master_Key]

It can be because it not instantaneous-induced diploe, its induced-induced dipole which is more stronger because it stays for a longer time at a particular energy without breaking.