Physics, Chemistry and Biology: Post your doubts here!

[princess sofia]

Explain plzzzz///////////// of how the method can b used to separate the two

crystallization ll be used
1. first heat the solution in an evaporating dish till point of crystallization
2. cool it untill crystals r formed
3. filter the crystals
4. wash wth distilled water
5. dry using filter paper

 

[Ameena Eesa]

crystallization ll be used
1. first heat the solution in an evaporating dish till point of crystallization
2. cool it untill crystals r formed
3. filter the crystals
4. wash wth distilled water
5. dry using filter paper

but they are mixed!

 

[Ameena Eesa]

Hey when iron is put in a testube containing water, it rusts. S0 why does level of water rise?

 

[Ameena Eesa]

Is there any logic like if a substance is put into water, and if it dissolves, it is ionic, and if it reacts, it is colvalent? Plsssssss help guys.

 

[Ameena Eesa]

And this one explain........................................

 

[Mai(M4!)]

implications to a species of cross-pollination??????????

 

[saif mahmoud]

when a nail is placed in water with no contact with oxygen does it rust
asap

 

[Zahidiiiii]

when a nail is placed in water with no contact with oxygen does it rust
asap

salty water and air containing oxygen are the best conditions of rust.........
since oxygen is not present Fe(2) doesnot oxides to Fe (3)......hence it doest not rust......
now dont tell me that the nail is made up of steel

 

[Zahidiiiii]

s

Is there any logic like if a substance is put into water, and if it dissolves, it is ionic, and if it reacts, it is colvalent? Plsssssss help guys.[/quoste]
sugar is covelently bonded hence there is a great difference in between dissoled solution and aqueous solution

 

[alla_saeed]

Ameena Eesa for the rusting question you asked , the water level rise because the oxygen which is the second major reason and vital substance taking part in the rusting process is used up in the space where it was present at the begining of the reaction , so water took its place , shown by the increase in its level .

Yes there is a rule for both ionic and covalent compounds when they are lowered in water , ionic do dissolve because in the process of dissolving there must be a compound which is strong enough to break the bonds present in water , and in ionic because of the positive and negative charges in the compound and the also the opposite charges in water ( H AND OH) that they do attract and accomplish the dissolving process.

Because covalent bonds lack of this properties and also because they are of weak attraction forces that they donnot have the power to break the bonds of water thus fails to dissolve in water .
but again covalent compounds doesnt dissolve in a covalent coumpound

Check more about polarity and nonpolarity in water .

hope to have answered your questions

 

[saif mahmoud]

salty water and air containing oxygen are the best conditions of rust.........
since oxygen is not present Fe(2) doesnot oxides to Fe (3)......hence it doest not rust......
now dont tell me that the nail is made up of steel

thanks alot ok
if there is oxygen but no water

 

[Zahidiiiii]

thanks alot ok
if there is oxygen but no water

us waqt b nhi ho ga.......bhai pani ki qadar kb samjho gy

 

[saif mahmoud]

implications to a species of cross-pollination??????????

firstly
1. it causes variation
2.the plant can survive to changing weather conditions
3.Diseases may not affect offspring as they are genetically dissimilar
4. depends on agents of pollination
5. insect may take pollen to a diff species of plants

hope i ans ur ques

 

[saif mahmoud]

us waqt b nhi ho ga.......bhai pani ki qadar kb samjho gy

i didnt understand what u have written english plz

 

[Zahidiiiii]

Ameena Eesa for the rusting question you asked , the water level rise because the oxygen which is the second major reason and vital substance taking part in the rusting process is used up in the space where it was present at the begining of the reaction , so water took its place , shown by the increase in its level .

Yes there is a rule for both ionic and covalent compounds when they are lowered in water , ionic do dissolve because in the process of dissolving there must be a compound which is strong enough to break the bonds present in water , and in ionic because of the positive and negative charges in the compound and the also the opposite charges in water ( H AND OH) that they do attract and accomplish the dissolving process.

Because covalent bonds lack of this properties and also because they are of weak attraction forces that they donnot have the power to break the bonds of water thus fails to dissolve in water .
but again covalent compounds doesnt dissolve in a covalent coumpound

Check more about polarity and nonpolarity in water .

hope to have answered your questions

we say that ionic compunds when lowered in water they disassociate themselves into ions rather then saying the term dissolving because some ionic compunnd do not dissolve in water....n colvent coumpunds don not disassociate them slves into ions

 

[Zahidiiiii]

i didnt understand what u have written english plz

in the absence of water iron will not rust........ now we know how important water is it is surely is a blessing

 

[saif mahmoud]

ok thanks

 

[alla_saeed]

thanks ! for explaining ! Zahidiiiii

 

[Zahidiiiii]

thanks ! for explaining ! Zahidiiiii

no prob. just need prayers .....beccz i know what really bad luck is from my past experience in ISLamiat

 

[saif mahmoud]

implications to a species of cross-pollination??????????

Mai(M4!)
1. leads to variation
2.offsprings can adapt to changing environment conditions
3. offsprings are not affected by diseases as they are genetically dissimilar
4. depends on agents of pollination
5. insect may carry pollen to diff species of plants