Chemistry: Post your doubts here!

[The Sarcastic Retard]

Your diagram is fine. Its the same as the marking scheme.

The first one is not same, I have drawn two Oxygen atoms as well which is not der in ms

 

[Metanoia]

The first one is not same, I have drawn two Oxygen atoms as well which is not der in ms

Erm, as I have explained. The 1st diagram is the incomplete answer. Students who produced the 1st diagram will only get 1 mark.

Students who produced the 2nd diagram gets 2 marks.

 

[The Sarcastic Retard]

Erm, as I have explained. The 1st diagram is the incomplete answer. Students who produced the 1st diagram will only get 1 mark.

Students who produced the 2nd diagram gets 2 marks.

I see... I thought 1 mark for the 1st dia and 2 marks for 2nd dia and so total 3 marks... *Phew* ty

 

[Studydayandnight]

T reacting with an excess of Na

NaO2CCH(ONa)CH2CO2Na ----> Over here Na, replaces the H in the alcohol group.

U reacting with an excess of Na2CO3

NaO2CCH(OH)CH(OH)CO2Na ---> Over here it doesn't. :s Why?

 

[The Sarcastic Retard]

T reacting with an excess of Na

NaO2CCH(ONa)CH2CO2Na ----> Over here Na, replaces the H in the alcohol group.

U reacting with an excess of Na2CO3

NaO2CCH(OH)CH(OH)CO2Na ---> Over here it doesn't. :s Why?

Are both question same?
What do u want the Mr of S , T and U or something else u wrote?

 

[Metanoia]

T reacting with an excess of Na

NaO2CCH(ONa)CH2CO2Na ----> Over here Na, replaces the H in the alcohol group.

U reacting with an excess of Na2CO3

NaO2CCH(OH)CH(OH)CO2Na ---> Over here it doesn't. :s Why?

Sodium metals react with OH, COOH
Sodium hydroxide react with COOH
sodium carbonates react with COOH.

 

[The Sarcastic Retard]

T reacting with an excess of Na

NaO2CCH(ONa)CH2CO2Na ----> Over here Na, replaces the H in the alcohol group.

U reacting with an excess of Na2CO3

NaO2CCH(OH)CH(OH)CO2Na ---> Over here it doesn't. :s Why?

Mr of S = 1 + 32 + 12 + 12 +1 + 12 + 1 + 12 + 32 + 1 = 116
Same way T = 134 And U = 150

 

[Studydayandnight]

Mr of S = 1 + 32 + 12 + 12 +1 + 12 + 1 + 12 + 32 + 1 = 116
Same way T = 134 And U = 150

Lol, that wasn't my doubt

It was why Na2CO3, didn't react with OH, turns out it just doesn't

Thanks though.

 

[Laila39]

Can someone please give me a list of all the flames we need to know? I cant find the appropriate ones anywhere! Please thanks guyss
-AS inorganic

 

[qwertypoiu]

Can someone please give me a list of all the flames we need to know? I cant find the appropriate ones anywhere! Please thanks guyss
-AS inorganic

Reaction with oxygen :
Sodium - golden yellow flame
Magnesium - sparkling bright flame (no colour)
Aluminum - bright flame (no color)
Phosphorus - yellow flame
Sulfur - pale blue flame

 

[Sarosh Jameel]

PLZ HELP ME WITH THIS ONE !

 

[psychiatrist]

Q6. From the relative abundance chart. Ratio of Isotope-10 : Isotope - 11 is 1:4

Q17. I saw the wrong question and explained for Q14.
Use your data booklet and locate the elements that represent the four options. Fill them in here before I explain further.
A.
B.
C.
D.

Q18. Again, us your data booklet write down the 1st, 2nd and 3rd IE of four options. Fill them in here before I explain further.
C
N
F
Na

Q27. From your understanding, how many protons, electrons and neutrons does Tc have?

Q6 : This is not taught in our school... 1/5 or 4/5 why only by 5?

Q17 :
A: Mg
B: Al
C: Si
D : P

Q18 :
C : 1090 2350 4610
N : 1400 2860 4590
F : 1680 3370 6040
Na : 494 4560 6940

Q27 :
p = 43 e = 43 n = 56

 

[ali_jaliawala]

Best Revision Portal!
Please help us in spreading the page so that maximum students can avail this opportunity!
https://www.facebook.com/alevels.revision

 

[ali_jaliawala]

Best Revision Portal!
Please help us in spreading the page so that maximum students can avail this opportunity!
https://www.facebook.com/alevels.revision

 

[asadalam]

Is So3 connected via PD PD forces or Van Der waals?Shouldnt it be PD PD Due to difference in e-vity of S and O?.Also are large scale uses of halogenoalkanes,naoh and other such compounds included.What are included.Also when HCL is dissolved is the bonding changed to form ions of H30 and Cl or due to hydrogen bonds being formed?

 

[Metanoia]

Q6 : This is not taught in our school... 1/5 or 4/5 why only by 5?

Q17 :
A: Mg
B: Al
C: Si
D : P

Q18 :
C : 1090 2350 4610
N : 1400 2860 4590
F : 1680 3370 6040
Na : 494 4560 6940

Q27 :
p = 43 e = 43 n = 56

Firstly, I've deleted my original explanation for Q18, I realized it was nonsensical after I reread it. Sorry about that.

Q6. The chart shows that for every 1 isotope that has 10 nucleons, there exist 4 isotopes with 11 nucleons.
This is the crucial interpretation you need to understand on the chart. The calculation is to find the average of each isotope.

If I were to reword the scenario as: for every 1 person who have $10 , there are 4 people with $11, what is average amount of money for each person?
(1 x 10 + 4 x 11)/5

Q17. Use data booklet and compare to the 2nd IE to the neighbors.
A: Mg (Compare to Na and Al) Does Mg has a higher 2nd IE than its neighbors? No.


B: Al (Compare to Mg and Si) Does Al has a higher 2nd IE than its neighbors? Yes.


C: Si (Compare to Al and P) Does Si has a higher 2nd IE than its neighbors? No.


D : P (Compare to Si and S) Does P has a higher 2nd IE than its neighbors? No.



Q18. Use the data booklet to compare the 1st IE of the options and the two elements that come after it.
A. Carbon (compared to nitrogen and oxygen)


B. Nitrogen (compared to oxygen and fluorine)


C. Fluorine (compared to Neon and Sodium)


D. Sodium (compared to magnesium and aluminum)


Based on the chart in the question, the 2nd element should have the highest IE and the 3rd element should have the lowest I.E. This fits option C.

Q27. You have already figured that there are 56 neutrons and 43 protons.
Statement 1: there are 13 more neutrons than protons. Thats correct isn't it?

 

[zain ul abidin]

Can anyone explain w13 43 q6 f(ii)

 

[Mahnoorfatima]

PLEASE SOMEONE HELP ME OUT ON THESE:
Okay so first, in a practical paper there is given a table where on the top it is written FA5, FA6 FA7 and on the side(vertical) it's written FA8 and FA9. And then it says that identify which of these ions are in which of these solutions. How am I supposed to know if to write the compound on top or bottom? FOR EXAMPLE:
FA6 Fa7 FA8
FA5 white ppt Yellow orange fizzing,colorless gas released.
ppt
insoluble

FA6 X Yellow ppt
insoluble in excess white ppt insoluble

FA7 X X NO change
We have to identify Pb2+, CL- , CO3-, CrO42-????

 

[Mahnoorfatima]

AND.. There's this expt hwere you have to find enthalpy of change using NH4CL, it's an endothermic reaction then there is a question where it says describe one major source of error of the expt. Exolain why ur suggestion would produce a more accurate value?

 

[Mahnoorfatima]

https://docs.google.com/viewerng/vi...wp-content/uploads/2012/11/9701_w14_qp_33.pdf
Q1 part f. HOW ARE WE SUPPOSED TO DRAW THE HESS CYCLE!!!?? Anyone?