Biology; Chemistry; Physics: Post your doubts here!

[Saad Mughal]

Trigonometry.
sin 30 = h / 10
h = 5 cm

Oh, so you're taking the movement of the block = 10 cm as hypotenuse. I get it.
It seems logical enough. Good Attempt.

 

[ijlalm]

One Question..How do we separate a mixture of two soluble salts??
Consider this equation: Ba(NO3)2 + MgCl2 ----> BaCl2 + Mg(NO3)2
Tell me whether the reaction is possible..OR NOT

 

[ijlalm]

Is the answer B? 1.1 m/s ? Maybe I've got it.

God knows!! I've tried to find the possible solution but to no avail.

 

[usama321]

One Question..How do we separate a mixture of two soluble salts??
Consider this equation: Ba(NO3)2 + MgCl2 ----> BaCl2 + Mg(NO3)2
Tell me whether the reaction is possible..OR NOT

don't know about your first question. About the second one, i don't think the reaction is possible, because Ba is more reactive than Mg, and NO3 is more stable then Cl, so Barium would tend to stick with the stabler compound.

 

[usama321]

what is the order of reactivity of negative ions such as sulphate, nitrate, chloride, iodide, carbonate
how do u find them n is it important to know it

i dont remember the complete table, but it starts with Chlorine, and down the group 7 elements, than hydroxide, NO3 and SO4. The upper elements are more reactive, therefore being less stable, and the lower ones are more stable

 

[usama321]

what is the order of reactivity of negative ions such as sulphate, nitrate, chloride, iodide, carbonate
how do u find them n is it important to know it

And you should learn the table, as it is of use in the electrolysis chapter too. It is simple, as the more reactive anions come at the top, and we know that the more reactive an anion is, the less stable it is. In electrolysis, you decide by this table which anion will be discharged at the anode. We know that in electrolysis, the less reactive anions are discharged, thus hydroxide is discharged the most easily at the anode (NO3 and SO4 are never discharged ). The only exception to this being when the solution contains a halogen ion in high concentration

 

[A star]

One Question..How do we separate a mixture of two soluble salts??
Consider this equation: Ba(NO3)2 + MgCl2 ----> BaCl2 + Mg(NO3)2
Tell me whether the reaction is possible..OR NOT

to your first question it depends on two factors
i) do you know what are those two salts
ii)whether you want both salts or not
some salts have different solubility in not and cold water thats one way
another combine them with a compound that would react with the impurity(the unwanted salt) then crystallise it

 

[usama321]

16
Which statement about catalysts is correct for a typical equilibrium reaction?
A A catalyst can be either an inorganic or an organic species.
B A catalyst does not take part in the reaction.
C A catalyst only speeds up the forward reaction.
D A catalyst provides the energy required to start a reaction.
Why in the world is the answer A and NOT B

 

[nidz]

16
Which statement about catalysts is correct for a typical equilibrium reaction?
A A catalyst can be either an inorganic or an organic species.
B A catalyst does not take part in the reaction.
C A catalyst only speeds up the forward reaction.
D A catalyst provides the energy required to start a reaction.
Why in the world is the answer A and NOT B

From what I know catalyst do take part in a reaction, (like they are lowering the activation energy.) but they only remain chemically unchanged after a reaction. That's why it is A :/

 

[falcon678]

16
Which statement about catalysts is correct for a typical equilibrium reaction?
A A catalyst can be either an inorganic or an organic species.
B A catalyst does not take part in the reaction.
C A catalyst only speeds up the forward reaction.
D A catalyst provides the energy required to start a reaction.
Why in the world is the answer A and NOT B

catalyst does take part in the reaction.....but aftr the reaction it is chemicaly same to wich v added before the reaction...thus ans is A not B !

 

[usama321]

From what I know catalyst do take part in a reaction, (like they are lowering the activation energy.) but they only remain chemically unchanged after a reaction. That's why it is A :/

catalyst does take part in the reaction.....but aftr the reaction it is chemicaly same to wich v added before the reaction...thus ans is A not B !

thanks

 

[papajohn]

One Question..How do we separate a mixture of two soluble salts??
Consider this equation: Ba(NO3)2 + MgCl2 ----> BaCl2 + Mg(NO3)2
Tell me whether the reaction is possible..OR NOT

Fractional distillation method

 

[usama321]

18
Which salt can be prepared by an acid-alkali titration method?
A ammonium sulphate
B copper(II) sulphate
C iron(II) sulphate
D zinc sulphate
anyone please?

 

[papajohn]

18
Which salt can be prepared by an acid-alkali titration method?
A ammonium sulphate
B copper(II) sulphate
C iron(II) sulphate
D zinc sulphateg
anyone please?

What i think is that for titration all reactants and product are soluble.. right so here ammonium sulphate is only soluble here.Then the answer must be A.

 

[usama321]

that is the correct answer. But what about d? Zn(OH)2 + H2SO4 = ZnSO4 + H2O?

(did not balance it)

 

[papajohn]

that is the correct answer. But what about d? Zn(OH)2 + H2SO4 = ZnSO4 + H2O?

You must know that ZN(OH)2 is the white precipitate..The precipitate is insoluble.

 

[usama321]

You must know that ZN(OH)2 is the white precipitate..The precipitate is insoluble.

isn't it soluble? :O

 

[papajohn]

Zn(OH)2 is precipitate.--- The emergence of the insoluble solid from solution is called precipitation.

 

[usama321]

Zn(OH)2 is precipitate.--- The emergence of the insoluble solid from solution is called precipitation.

i know that, but it dissolves in excess of NaOH, so there must be some solubility

 

[Saad Mughal]

18
Which salt can be prepared by an acid-alkali titration method?
A ammonium sulphate
B copper(II) sulphate
C iron(II) sulphate
D zinc sulphate
anyone please?

A is the answer. We make ammonium salts and group 1 salts using titration.