Nemidav:
equation:H2SO4 + CuO-> CuSO4 + H20
MASS NUMB OF H2SO4=98g
MASS NUMB OF CuO=79.5g
if 98g of H2SO4 will react with 79.5g of CuO
then 4.9g of H2SO4 will react with xg of CuO
THEN X=79.5*4.9/98
x=465.5/98=3.95
3.95 approx 4.
Ans=A

mayorall:

The answers are correct but its not mass number its molar mass H2SO4 and CuO are compound....

Please do you understand how he arrived at the answers...if No...we can use a formular method.

Nemidav: Pls teach us d formular method too.

mayorall: What volume of gas is involved at s.t.p if 2g of caco3 is added to a solution of HCl

a.224cm3
b.112cm3
c.240cm3
d.448cm3

mayorall: Let more questions come in......

t.boy007:
please teach us the calculations in energetics.....i mean all those heat of combustion,formation,e.t.c

Kunlexic: This is on electrolysis(Electrochemistry)
1.state the two laws of Michael Faraday on electrolysis
2.Calculate the current that will deposit 0.16g of copper in 15minutes from copper(III)tetraoxosulphate(VI) solution.

Kunlexic: This is on electrolysis(Electrochemistry)
1.state the two laws of Michael Faraday on electrolysis
2.Calculate the current that will deposit 0.16g of copper in 15minutes from copper(III)tetraoxosulphate(VI) solution.

mayorall: N2 + 3H3 <===> 2NH3 Dh = -92kjmol^-1

The equilibrium constant for the reaction can be expressed as

A.Kc = 2[NH3]/3[H2] [N2]

B.Kc = [NH3]^2/[N2] [H2]^3

C. Kc = [N2] [H2}^3/{NH3}^2

D. Kc = 3[H2] [N2]/2[NH3]

Kunlexic: This is on electrolysis(Electrochemistry)
1.state the two laws of Michael Faraday on electrolysis
2.Calculate the current that will deposit 0.16g of copper in 15minutes from copper(III)tetraoxosulphate(VI) solution.

mayorall: N2 + 3H3 <===> 2NH3 Dh = -92kjmol^-1

The equilibrium constant for the reaction can be expressed as

A.Kc = 2[NH3]/3[H2] [N2]

B.Kc = [NH3]^2/[N2] [H2]^3

C. Kc = [N2] [H2}^3/{NH3}^2

D. Kc = 3[H2] [N2]/2[NH3]

joseboy199:
continuation,,guy d equatn z nt balancd,hydrogen gas should av 3 mole..i.e 3H2,,,and is written as [H2]*3...and nitrogen is written as [N2] cuz d numba of mole z 1

joseboy199:
nxt tym complete ur questn...u didnt gv us d electrochemical equivalent e.c.e...
steps 2 4low on aw 2 solve d que
formula 2 use z...M=ZIt,,whr
M=mass in gramms
Z=e.c.e
I=current in amperes
t=time
0.16=15*60(input d z here)*I
I=0.16/15*60*z
solve wen z gven by im

joseboy199:
Ans is B
equilibrium constant Kc=products/reactants.
it is products over d reactants...the law bhind aw equilibrium constant Kc is law of active mass
the number of mole of each compounds is written inform of power.e.g 2NH3 wic z naw written as {NH3}*2,

Nemidav: My brodas,who cn explain calculation based on faraday's law?dunno y ts giving me problems.

buzyguy: Which of the following can be adopted to prevent rustinga)eletrolytic,cathodic protectn by making zinc the cathode and iron the anode (b)electrolytic cathodic protection with the anode zinc and cathode iron (c)electrochemical,with the anode iron and cathode zinc (d)electrochemical,with the anode iron and cathode tin?

mayorall:

B is the answer as zinc have to lose electrons xo etas to be the anode as the positive electrode...The process is called galvanisation...

mayorall:

B is the answer as zinc have to lose electrons xo etas to be the anode as the positive electrode...The process is called galvanisation...

mayorall:

B is the answer as zinc have to lose electrons xo etas to be the anode as the positive electrode...The process is called galvanisation...

buzyguy: Itz electrochemical wen zinc acts as the anode nd fe,cathode bcuz znc z grter dan iron in da e.c.e series.i bliev u already knw dat,nd electrolytc wen znd z cathode nd iron z anode...u knw wen u get to electrolytc cells,itz alwyz reversed to da combinatn in electrochmical cell.hop it makz sense?!

Nemidav: My brodas,who cn explain calculation based on faraday's law?dunno y ts giving me problems.

Kunlexic:
4rm d 1st law:m¤Q but Q=it,.'.m=KIt.
The mass of d element discharge depends on i.the magnitude of current dat is passed ii.the time taken 4 d current to pass
when a graph of mass(kg) is plotted againdt the time in sec or currunt in ampere,a straight line grahj will be obtained.
4rm d 2nd law,we have dat 1e-=1F=96500C E.g CuSO4 and AgNO3 are different electrolytes wen d same qty of electricity is passed 2ru it CuSO4--Cu^2+ SO4^2-
Cu^2+ + 2e-=Cu,2e-=2F=1 mol of Cu
from AgNO3,Ag+ + e-=Ag,here 1e-=1F=1 mol of Ag
N.B-If x moles of copper is produce then the moles of silver that will be produced will be 2x moles.

buzyguy: Hw many atoms r there in 2moles of hydrogen moleculez? Itz calculatn o