Physics, Chemistry and Biology: Post your doubts here!

[fishcook]

fishcook explains it in a good way,

cause they say that each mole produces H+ ions in the question

 

[kainat husain]

i think you find it out by titration, using an indicator and comparing the volumes of acid used to neutralize lets say 25cm3 of NaOH
the one that uses less acid is H2Y so the one that uses more is HY... Im not sure though.

hmm ok actually its for 2000 so forge tit

 

[kainat husain]

sorry, link plz?

i dun have link! xtreem papers dsnt have

 

[AAnsarii]

i dun have link! xtreem papers dsnt have

5n i think fishcook gave d ryt 1.

 

[kainat husain]

Mg + 2H+ > Mg+2 + H2

plzzz explain how did u do

 

[AAnsarii]

plzzz explain how did u do

mg is in metal state, so no charge. h is in acid so +(coz H is always +ve), in H2SO4, so 2 hydrogen atoms, so 2H+ ions
im a bad xplainer, so sorry if u didnt get it

 

[Moi]

really, no, y do dat?
lyk acid donates H+ ions, rite? plz reply asap, n thx

if you think about it...if you are going to get rid of both OH from the alcohol why put it in the first place ??
In condensatio polymarization, polyeters, you have dicarboxylic acid and dialcohol ... so when you come to remove the said elemants to have a polymer, you remove the OH from the acid, (Both) and H from the alcohol (both).


sorry bad drawing but the best i can to show you!!

 

[fishcook]

in an ionic equation you have to write the charges of the atoms/ions, like a redox reaction.
if they say symbol then you have to write the compounds and their products

 

[thats_me]

d- the formula of an acid is either of the type HY or H2Y.How could you find out which one is correct by using Aq.solutions of the acid and of sodium hydroxide. Assume that both solutions have the same concentration, 0.1 mol/dm3
please help!

Alright..
HY-monoprotic(HCL, HNO3)
H2Y-diprotic (H2CO3,H2SO4)
By Titration
NaOH +HCl -->NaCl +H2O
Ratio :1:1
2NaOH +H2SO4-->NaSO4 +H2O
Ratio :2:1
Prepare the same conc of NaOH as the unknown acid
pipette out 25cm3 of unknown acid and add a few drops of suitable indicator
Fill burette with NaOH solution till zero Mark and run the burette dropwise until indicator just changes colour
record the volume of NaOH used
If the volume ratio is 1:1 then the acid is HY type else H2Y type

 

[imperial]

plzzz explain how did u do

ok

the normal equation is:

Mg + H2SO4 -> MgSO4 + H2

anything (aq) must be written in ion format, anything else SAME

Mg + H+ + SO4-2 -> Mg+2 + SO4- + H2

delete ions that are same in the reactants and the products sides (in this case only sulphate, note that Mg is solid and Mg+2 is ion so dont delete, and H2 is gas and H+ is ion so dont delete)

Mg + H+ -> Mg+2 + H2

Balance

Mg + 2H+ -> Mg+2 + H2

 

[AAnsarii]

Alright..
HY-monoprotic(HCL, HNO3)
H2Y-diprotic (H2CO3,H2SO4)
By Titration
NaOH +HCl -->NaCl +H2O
Ratio :1:1
2NaOH +H2SO4-->NaSO4 +H2O
Ratio :2:1
Prepare the same conc of NaOH as the unknown acid
pipette out 25cm3 of unknown acid and add a few drops of suitable indicator
Fill burette with NaOH solution till zero Mark and run the burette dropwise until indicator just changes colour
record the volume of NaOH used
If the volume ratio is 1:1 then the acid is HY type else H2Y type

oyee, 2NaOH +H2SO4-->Na2SO4 + 2H2O, i think
im getting all wrong notions?

 

[Moi]

what i mean that there is should be double bonded C

C=C

(generally in esters, i hope you got what i mean)

no the double bond is C=O because C=C is alkenes

 

[imperial]

no the double bond is C=O because C=C is alkenes

i knew about just was lazy to correct (the question was talking about acid and not ester )

 

[thats_me]

oyee, 2NaOH +H2SO4-->Na2SO4 + 2H2O, i think
im getting all wrong notions?

yea sorry forgot to balance

 

[IsraJ]

can anyone help me with may june 2009 paper 61 question 5 b?

 

[thats_me]

can anyone help me with may june 2009 paper 61 question 5 b?

61?

 

[kainat husain]

mg is in metal state, so no charge. h is in acid so +(coz H is always +ve), in H2SO4, so 2 hydrogen atoms, so 2H+ ions
im a bad xplainer, so sorry if u didnt get it

no no thnx i got it but y in the product thingy H has no charge Mg + 2H+ > Mg+2 + H2

 

[IsraJ]

yes!

61?

 

[thats_me]

yes!

subject?

 

[kainat husain]

ok

the normal equation is:

Mg + H2SO4 -> MgSO4 + H2

anything (aq) must be written in ion format, anything else SAME

Mg + H+ + SO4-2 -> Mg+2 + SO4- + H2

delete ions that are same in the reactants and the products sides (in this case only sulphate, note that Mg is solid and Mg+2 is ion so dont delete, and H2 is gas and H+ is ion so dont delete)

Mg + H+ -> Mg+2 + H2

Balance

Mg + 2H+ -> Mg+2 + H2

i got u like i knw how to do this
but when we have to make silver chloride we'll do this?
normal eq- AgNO3 + NaCl ------> AgCl + NaNO
NOW how to make this an ionic eq?