Biology; Chemistry; Physics: Post your doubts here!

[secret lover]

You are in O Levels thread ..

yh by mistake i enetered it..but do u hav any idea abt it?

 

[syed1995]

yh by mistake i enetered it..but do u hav any idea abt it?

Zinc + Steam --> Zinc Oxide + Hydrogen

Cond. Hot water/Steam.

Sr + 2H2O --> Sr(OH)2 +H2

Cold Water.

 

[secret lover]

Zinc + Steam --> Zinc Oxide + Hydrogen

Cond. Hot water/Steam.

Sr + 2H2O --> Sr(OH)2 +H2

Cold Water.

ohkay tanx aloott

 

[kitecrystal]

Two different hydrocarbons each contain the same percentage by mass of hydrogen.
It follows that they have the same
A empirical formula.
B number of isomers.
C relative molecular mass.
D structural formula.

 

[khizer shahab]

Two different hydrocarbons each contain the same percentage by mass of hydrogen.
It follows that they have the same
A empirical formula.
B number of isomers.
C relative molecular mass.
D structural formula.

option A !!! due to same percentage of mass of hydrogen!!!

 

[kitecrystal]

option A !!! due to same percentage of mass of hydrogen!!!

thanku

 

[khizer shahab]

is there any catalyst for haber process!!???

 

[SalmanPakRocks]

is there any catalyst for haber process!!???

It's Iron.

 

[ashiqbal]

ashhab bhai aaj tu barray khush lag rahay hain Kia baat hai =D ..

yaar in donon kai comments parh kai itni hansi aayi, bus kia karun!

 

[SalmanPakRocks]

Assalam O Alaikum Ashhab bhai .. Tayyari aik dum fit ? .. Kal kaaa Kiaaaa hoga ab :\

Use english and no off-topics

 

[ashiqbal]

hmm.. hopefully, gud preparation! Inshallah, i will get good grades! syed1995
and lets see what CIE has to throw at us! lets show them the power of XPF!

 

[syed1995]

hmm.. hopefully, gud preparation! Inshallah, i will get good grades! syed1995
and lets see what CIE has to throw at us! lets show them the power of XPF!

Yea .. we are prepared for anything they throw at us .. but I have a humble request for CIE, "Whatever you throw at us, please make it soft and easy."

 

[rabiafarooq101]

bol everyone

 

[syed1995]

bol everyone

best of luck to you too

 

[syed1995]

hmm.. hopefully, gud preparation! Inshallah, i will get good grades! syed1995
and lets see what CIE has to throw at us! lets show them the power of XPF!

ashhab bhai .. In Energy change ..

If Ep is less than Er ... Reaction is Exothermic ... Delta H = Negative

if Ep is greater than Er .. Reaction is Endothermic .. right? Delta H = Positive

 

[ashiqbal]

ashhab bhai .. In Energy change ..

If Ep is less than Er ... Reaction is Exothermic ... Delta H = Negative

if Ep is greater than Er .. Reaction is Endothermic .. right? Delta H = Positive

yes! delta H = Ep - Er, no matter what! and in endo, Ep is greater!
paper denay nahin jaana kia???

 

[syed1995]

yes! delta H = Ep - Er, no matter what! and in endo, Ep is greater!
paper denay nahin jaana kia???

Jaayeingay, Jaayeingay .. Jaldi kis baat ki hai

Anyways yeah, Delta H = Ep-Er

Endo = R+Heat ---> P
Exo = R ----> P + Heat

 

[gelato]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s11_qp_32.pdf
Can anyone please answer 3 a)i) & ii) ? Thank you sooooooo much

 

[ashiqbal]

paper ho gaya!
lost one mark for sure, baqion ka pata nahin!

 

[ashiqbal]

Jaayeingay, Jaayeingay .. Jaldi kis baat ki hai

Anyways yeah, Delta H = Ep-Er

Endo = R+Heat ---> P
Exo = R ----> P + Heat

glad that i cleared that up?