Chemistry: Post your doubts here!

[Metanoia]

Is the mass of total products always equal to the mass of reactants used?

Yes, that's right. Conservation of mass.

 

[The Sarcastic Retard]

Q15 how u find total mass?

1000 + 200

 

[forest822]

Water is added to anhydrous aluminium chloride to make a 0.1 mol dm-3 solution.
Which observations are correct?
1 The reaction is endothermic.
Why this statement is incorrect?

 

[The Sarcastic Retard]

Water is added to anhydrous aluminium chloride to make a 0.1 mol dm-3 solution.
Which observations are correct?
1 The reaction is endothermic.
Why this statement is incorrect?

Enthalpy change of hydration is always exothermic, not sure, but till now I have not come up with a question of it with Endothermic. If u know some reaction that is endothermic do lemme know!! Thanks.

 

[forest822]

Enthalpy change of hydration is always exothermic, not sure, but till now I have not come up with a question of it with Endothermic. If u know some reaction that is endothermic do lemme know!! Thanks.

Why this is enthalpy change of hydration instead of enthalpy change of solution? Thank you !

 

[The Sarcastic Retard]

Why this is enthalpy change of hydration instead of enthalpy change of solution? Thank you !

Both are different.

 

[SadiaMaryam]

Why this is enthalpy change of hydration instead of enthalpy change of solution? Thank you !

enthalpy of change hydration is the enthalpy change when "gaseous atoms" dissolve in water while enthalpy of solution is when "ionic compound' dissolves in water.. u can check whats going in your question and relate.

 

[The Sarcastic Retard]

Why this is enthalpy change of hydration instead of enthalpy change of solution? Thank you !

Here its the SEC of hydration of anhydrous salt.

 

[awesomaholic101]

can someone plz explain the 37th one?

 

[The Sarcastic Retard]

View attachment 57387
can someone plz explain the 37th one?

I was not aware of this thing till this paper came. That was a guess of mine and hopefully it was correct.
Connecting carbon should be sp^2 hybrydised. So, 1 and 2 are Sp2 but 3 is sp3.

 

[SadiaMaryam]

View attachment 57387
can someone plz explain the 37th one?

there is no free rotation around carbon to carbon double bond and therefore structures with c to c double bonds lie in the same plane...the third one does not have carbon to carbon double bond in the labelled carbons, the double bond shown is with O

 

[manya]

help plz
this is a paper 5 question, that means no application booklet, so how am i supposed to write the equation without it

 

[Sinzzzz]

hey!!
can someone please explain this:
When a sample of HI is warmed to a particular temperature the equilibrium below is established.
2HI(g) H2(g) + I2(g)
At this temperature, it is found that the partial pressure of HI(g) is 28 times the partial pressure of H2(g). What is the value of Kp at this temperature?
A 1.28 × 10–3
B 0.035
C 28
D 784
The answer is A.
Thank you!!

 

[The Sarcastic Retard]

hey!!
can someone please explain this:
When a sample of HI is warmed to a particular temperature the equilibrium below is established.
2HI(g) H2(g) + I2(g)
At this temperature, it is found that the partial pressure of HI(g) is 28 times the partial pressure of H2(g). What is the value of Kp at this temperature?
A 1.28 × 10–3
B 0.035
C 28
D 784
The answer is A.
Thank you!!

P^2(HI) = (28)^2
P(H2) = 1
P(I2) = 1
Kp = P(H2).P(I2) / P^2(HI)
Kp = A

 

[The Famous One]

When I solve recent years past papers that is from 2007 to 2015(summer) summer and witner both I use to score always above 50. Now when I look into old years like this paper I ended up at the score of just 46. I have so many doubts in this paper. If anyone can help me out solving, Q1(c)(d), Q2(c)(d), Q5(c), Q7(b)(c) in Q7(b) arent answer in ms for uses of esters? Please do it as soon as possible. Also, When I was solving papers I found that mostly moles thingy are in summer papers, in winter papers its mostly inorganic part and theory. Am I correct? Should I expect 2015 november paper to be easier with moles thingy??

Thank you,
Regards,
XPC member,
The Sarcastic Retard

imma do you still need them?

 

[Sinzzzz]

can someone please explain question 37 in this paper

 

[The Sarcastic Retard]

imma do you still need them?

No thanks.

 

[The Sarcastic Retard]

can someone please explain question 37 in this paper

The connecting carbon (C) should be sp2 hybridizes.
1 and 2 are sp2 hybridised and 3 is sp3.

 

[The Sarcastic Retard]

 

[The Sarcastic Retard]

imma do you still need them?

Solve these :~
https://www.xtremepapers.com/commun...qs-9701-and-9702-discussion-here.42450/page-4 (my doubts are at last posts of the page 4 and starting of page 5) Thanks.