Chemistry: Post your doubts here!

[Akshajistari]

Please explain. The answer is B.

Saad the Paki My Name

 

[Akshajistari]

Koi Hai? >>__<<

 

[Saad the Paki]

Please explain. The answer is B.View attachment 59447

Saad the Paki My Name

The only difficult thing here is to form the equations, which u have to do by balancing the oxidation numbers.
Once the equation is there, find the moles of Sn2+, and then do the ratio thing.

 

[Akshajistari]

The only difficult thing here is to form the equations, which u have to do by balancing the oxidation numbers.
Once the equation is there, find the moles of Sn2+, and then do the ratio thing.

Thanks! Someone had helped in another thread already, but this makes it even clearer.

 

[My Name]

Koi Hai? >>__<<

Didn't get tag alert? :/

 

[Saad the Paki]

Didn't get tag alert? :/

Me neither. ....

 

[Akshajistari]

Challo, ab to pata chal gaya...

 

[Eugene99]

Challo, ab to pata chal gaya...

this signature of yours! Haha XD... causes a lot of trouble!

 

[Akshajistari]

this signature of yours! Haha XD... causes a lot of trouble!

 

[Syed Umar]

Heyy, I need help solving the Hess law questions and the enthalpy changes of formation and combustion etc.
All of them seem to have a different way to them. Any help?

 

[Awesome12]

Heyy, I need help solving the Hess law questions and the enthalpy changes of formation and combustion etc.
All of them seem to have a different way to them. Any help?

There is a simple concept behind them. Why not post a question?

 

[Syed Umar]

Which compound might X be? In its reaction with sodium, 1mol of a compound X gives 1mol of H2(g).

A CH3CH2CH2CH2OH B (CH3)3COH C CH3CH2CH2CO2H D CH3CH(OH)CO2H

Answer is D, but how?

 

[Syed Umar]

There is a simple concept behind them. Why not post a question?

I'll let you know next I see one..

 

[Syed Umar]

There is a simple concept behind them. Why not post a question?

What is the enthalpy change under standard conditions for the following reaction? The standard enthalpy changes of formation of iron(II) oxide, FeO(s), and aluminium oxide, Al2O3(s), are and –266kJmol–1 and -1676kJmol-1 respectively.

What is the enthalpy change under standard conditions for the following reaction?


2O3(s)(s) 3Fe(s) + Al 3FeO(s) + 2Al

Shouldn't it be Reactants - Products?
So, 3x(-266) - (-1676)= +878kJmol-1?

 

[qwertypoiu]

Which compound might X be? In its reaction with sodium, 1mol of a compound X gives 1mol of H2(g).

A CH3CH2CH2CH2OH B (CH3)3COH C CH3CH2CH2CO2H D CH3CH(OH)CO2H

Answer is D, but how?

One MOLE of H2 means there must be TWO Hydrogen atoms released per molecule being released.

Compound A and B both only have one alcohol functional group. Both will release ONE Hydrogen atom per molecule, but that will only be HALF a mole of H2.
Compound C only has one carboxylic acid group and so releases only HALF a mole of H2.
Compound D has one carboxylic acid group and one alcohol group. In total, it will release TWO hydrogen atoms per molecule which is same as saying ONE mole of H2 per mole of compound.

 

[qwertypoiu]

What is the enthalpy change under standard conditions for the following reaction? The standard enthalpy changes of formation of iron(II) oxide, FeO(s), and aluminium oxide, Al2O3(s), are and –266kJmol–1 and -1676kJmol-1 respectively.

What is the enthalpy change under standard conditions for the following reaction?


2O3(s)(s) 3Fe(s) + Al 3FeO(s) + 2Al

Shouldn't it be Reactants - Products?
So, 3x(-266) - (-1676)= +878kJmol-1?

What you have written doesn't look like a reaction to me.

 

[Sunit Saha]

Hey guys! I wanted to ask that do you guys have any idea where I can get the sample paper of May/June 2016 for As level chem?

 

[Syed Umar]

What you have written doesn't look like a reaction to me.

oh sorry.




3FeO(s) + 2Al(s) = 3Fe(s) + Al2O3(s)

 

[Syed Umar]

One MOLE of H2 means there must be TWO Hydrogen atoms released per molecule being released.

Compound A and B both only have one alcohol functional group. Both will release ONE Hydrogen atom per molecule, but that will only be HALF a mole of H2.
Compound C only has one carboxylic acid group and so releases only HALF a mole of H2.
Compound D has one carboxylic acid group and one alcohol group. In total, it will release TWO hydrogen atoms per molecule which is same as saying ONE mole of H2 per mole of compound.

THANKK YOU!!

 

[Syed Umar]

Which reagent would react with prop-2-en-1-ol to form a product that could exist as optical isomers?
Why is it bromine and not PCl5?