Physics, Chemistry and Biology: Post your doubts here!

[Kiara P.]

Me too,best of luck for ur night!!!!!!!!!!!1

Thank you and same to youu !

 

[shingiechingz@8]

who is gonna study all night for chemistry p3 and p1?

me dude

 

[sj0007]

about the oxidation of the ethanol

By potassium mangnate?
I dont think its required
but It depends whether the permanganate is a) in excess and b) has been sufficiently acidified.
C2H5OH ---MnO4------> CH3CHO + H20
CH3CHO ---MnO4------> CH3COOH
^I googled the answer............

 

[sj0007]

I wanted to ask how to work this out? The mass of one mole of an alcohol is 116g. What is its formula?

See here:
https://www.xtremepapers.com/commun...t-your-doubts-here.11053/page-405#post-911043
I had answered the same ques

 

[ThePacifics]

See here:
https://www.xtremepapers.com/commun...t-your-doubts-here.11053/page-405#post-911043
I had answered the same ques

thanks a lot!

 

[shingiechingz@8]

I wanted to ask how to work this out? The mass of one mole of an alcohol is 116g. What is its formula?

i think you should use the the general formula CnH2n+1OH=116
which is 12n+(2n+1)+16+1=116
14n+18=116
14n/14=(116-18)/14
n=7
therefore alocohol is C7H15OH

 

[shingiechingz@8]

1,2g of magnesium reacts with a solution containing 2,74g of Hydrochloric acid .
what is the limiting reactant ?

 

[DXDEVIL130]

1,2g of magnesium reacts with a solution containing 2,74g of Hydrochloric acid .
what is the limiting reactant ?

HCL is in excess and Mg is the limiting reagent.
You first find the moles of both of them, and whichever has less number of moles is the limiting reagent, since the ratio between Mg and HCL is 1:1.

 

[shingiechingz@8]

HCL is in excess and Mg is the limiting reagent.
You first find the moles of both of them, and whichever has less number of moles is the limiting reagent, since the ratio between Mg and HCL is 1:1.

may you pliz show your workin

 

[Muaaz Iqbal]

Best Of luck Guy's !!

 

[shingiechingz@8]

Best Of luck Guy's !!

thanx

 

[DXDEVIL130]

may you pliz show your workin

2Mg+2HCl => 2MgCl+H2
Moles=Mass/Mr
Mg=1.2/24= 0.05
HCl=2.74/1+35.5=0.08
FROM EQUATION Mg:HCl= 2:2 = 1:1, which means both should be equal, but HCl is more than 0.05, thus it's in excess and Mg is the limiting reagent.

 

[shingiechingz@8]

2Mg+2HCl => 2MgCl+H2
Moles=Mass/Mr
Mg=1.2/24= 0.05
HCl=2.74/1+35.5=0.08
FROM EQUATION Mg:HCl= 2:2 = 1:1, which means both should be equal, but HCl is more than 0.05, thus it's in excess and Mg is the limiting reagent.

should it be MgCl or MgCl2 as Mg2+ combined with Cl- =MgCl2?

 

[DXDEVIL130]

should it be MgCl or MgCl2 as Mg2+ combined with Cl- =MgCl2?

Oops, my bad, it's mgcl2
Mg+2HCl => MgCl2+H2

So the ratio Mg:HCl would be 1:2, so if Mg is 0.05 moles, then HCl should be 0.05*2 which is 0.1, but it's only 0.08, so HCl is the limiting reagent.

 

[shingiechingz@8]

how does respiration increases co2 content in the atmosphere?

 

[Ahmed Elsiddig]

 

[Ahmed Elsiddig]

HELP PLEASE

 

[DANISH182]

who is still studying for chemistry!!!

 

[shingiechingz@8]

who is still studying for chemistry!!!

me

 

[Sara Marques]

who is still studying for chemistry!!!

Unfortunately me! until tomorrow afternoon