Chem.p34 answer discussion...

[SabaTariqNiaz]

Wasnt it supposed 2 be redox??
Thts wht m frnd wrote... i ended up wth oxidation!

It was redox

 

[aaditya menon]

+3 -3, definitely.

 

[Saad (سعد)]

Wasnt it supposed 2 be redox??
Thts wht m frnd wrote... i ended up wth oxidation!

Hmm... I think both are correct.

 

[Beaconite]

My Q2 was like this:

FA5 (i) Effervescence noted, brown gas released which is identified as NO2 due to color
(ii) Effervescence, Solution turns brown, black-brown ppt formed which dissolves and brown gas NO2 given off, identified due to color
(iii) Purple color of KMNo4 decolorised, effervescence, brown gas given off, identified as NO2 due to color.

FA6 (i) Missed because of time.
(ii) Dissolves to form colorless solution in H2O. Heating with NaOH(aq) causes colorless gas to be evolved, turns red litmus blue. Identified as NH3

FA7 (i) Melts into colorless liquid. Upon standing, first becomes colorless suspension then white solid obtained when water evaporates.
(ii) Dissolves to form colorless solution in H2o. Upon heating with NaOH(aq), colorless gas evolved, turns blue litmus red.

Element: Nitrogen
OS: +3, +1
Type: Oxidation

b)
Reagents: NaOH(aq), NH3(aq)

FB8 (i) Add 1cm depth NaOH (aq) to 1cm depth FB8, then add excess NaOH(aq) Greenish ppt formed insoluble in excess (forgot exact color)
(ii) Add 1cm depth NH3 (aq) to 1 cm depth FB8, then add excess NH3(aq) Blue solution formed

FB9 (i) Add 1cm depth NaOH(aq) to 1cm depth FB9, then add excess NaOH(aq) Pale green ppt formed, insol. in excess
(ii) Add 1cm depth NH3(aq) to 1 cm depth FB9, then add excess NH3(aq) Pale green ppt formed, insol. in excess

(The table above was really cramped for FB9, so I wrote legibly but very small.)

FB9
Explanation: Observations made match notes on chart.

Missed the last two parts of the question. How many marks out of 14-16 (the no. of marks it was worth) should I expect in this question?

 

[angelgirl:)]

My Q2 was like this:

FA5 (i) Effervescence noted, brown gas released which is identified as NO2 due to color
(ii) Effervescence, Solution turns brown, black-brown ppt formed which dissolves and brown gas NO2 given off, identified due to color
(iii) Purple color of KMNo4 decolorised, effervescence, brown gas given off, identified as NO2 due to color.

FA6 (i) Missed because of time.
(ii) Dissolves to form colorless solution in H2O. Heating with NaOH(aq) causes colorless gas to be evolved, turns red litmus blue. Identified as NH3

FA7 (i) Melts into colorless liquid. Upon standing, first becomes colorless suspension then white solid obtained when water evaporates.
(ii) Dissolves to form colorless solution in H2o. Upon heating with NaOH(aq), colorless gas evolved, turns blue litmus red.

Element: Nitrogen
OS: +3, +1
Type: Oxidation

b)
Reagents: NaOH(aq), NH3(aq)

FB8 (i) Add 1cm depth NaOH (aq) to 1cm depth FB8, then add excess NaOH(aq) Greenish ppt formed insoluble in excess (forgot exact color)
(ii) Add 1cm depth NH3 (aq) to 1 cm depth FB8, then add excess NH3(aq) Blue solution formed

FB9 (i) Add 1cm depth NaOH(aq) to 1cm depth FB9, then add excess NaOH(aq) Pale green ppt formed, insol. in excess
(ii) Add 1cm depth NH3(aq) to 1 cm depth FB9, then add excess NH3(aq) Pale green ppt formed, insol. in excess

(The table above was really cramped for FB9, so I wrote legibly but very small.)

FB9
Explanation: Observations made match notes on chart.

Missed the last two parts of the question. How many marks out of 14-16 (the no. of marks it was worth) should I expect in this question?

MashaAllah...goood memory...

 

[aaditya menon]

My Q2 was like this:

FA5 (i) Effervescence noted, brown gas released which is identified as NO2 due to color
(ii) Effervescence, Solution turns brown, black-brown ppt formed which dissolves and brown gas NO2 given off, identified due to color
(iii) Purple color of KMNo4 decolorised, effervescence, brown gas given off, identified as NO2 due to color.

FA6 (i) Missed because of time.
(ii) Dissolves to form colorless solution in H2O. Heating with NaOH(aq) causes colorless gas to be evolved, turns red litmus blue. Identified as NH3

FA7 (i) Melts into colorless liquid. Upon standing, first becomes colorless suspension then white solid obtained when water evaporates.
(ii) Dissolves to form colorless solution in H2o. Upon heating with NaOH(aq), colorless gas evolved, turns blue litmus red.

Element: Nitrogen
OS: +3, +1
Type: Oxidation

b)
Reagents: NaOH(aq), NH3(aq)

FB8 (i) Add 1cm depth NaOH (aq) to 1cm depth FB8, then add excess NaOH(aq) Greenish ppt formed insoluble in excess (forgot exact color)
(ii) Add 1cm depth NH3 (aq) to 1 cm depth FB8, then add excess NH3(aq) Blue solution formed

FB9 (i) Add 1cm depth NaOH(aq) to 1cm depth FB9, then add excess NaOH(aq) Pale green ppt formed, insol. in excess
(ii) Add 1cm depth NH3(aq) to 1 cm depth FB9, then add excess NH3(aq) Pale green ppt formed, insol. in excess

(The table above was really cramped for FB9, so I wrote legibly but very small.)

FB9
Explanation: Observations made match notes on chart.

Missed the last two parts of the question. How many marks out of 14-16 (the no. of marks it was worth) should I expect in this question?

Redox

+3/-3

And gotta right crystallization or something, cross checked it with many for FA7 i)

 

[Beaconite]

Thanks. What about the rest? Is that alright?

 

[aaditya menon]

"FB9 (i) Add 1cm depth NaOH(aq) to 1cm depth FB9, then add excess NaOH(aq) Pale green ppt formed, insol. in excess
(ii) Add 1cm depth NH3(aq) to 1 cm depth FB9, then add excess NH3(aq) Pale green ppt formed, insol. in excess"

^^ Turns brown when in contact with air (it actually did).

And yea, I guess the rest are correct (Whatever you've missed out, Idon't remember those, but they were easy. There was this red brown ppt formed when KMnO4 is added to FB9)

 

[Beaconite]

The last two parts were worth how many marks again?

 

[mariamalik]

My Q2 was like this:

FA5 (i) Effervescence noted, brown gas released which is identified as NO2 due to color
(ii) Effervescence, Solution turns brown, black-brown ppt formed which dissolves and brown gas NO2 given off, identified due to color
(iii) Purple color of KMNo4 decolorised, effervescence, brown gas given off, identified as NO2 due to color.

FA6 (i) Missed because of time.
(ii) Dissolves to form colorless solution in H2O. Heating with NaOH(aq) causes colorless gas to be evolved, turns red litmus blue. Identified as NH3

FA7 (i) Melts into colorless liquid. Upon standing, first becomes colorless suspension then white solid obtained when water evaporates.
(ii) Dissolves to form colorless solution in H2o. Upon heating with NaOH(aq), colorless gas evolved, turns blue litmus red.

Element: Nitrogen
OS: +3, +1
Type: Oxidation

b)
Reagents: NaOH(aq), NH3(aq)

FB8 (i) Add 1cm depth NaOH (aq) to 1cm depth FB8, then add excess NaOH(aq) Greenish ppt formed insoluble in excess (forgot exact color)
(ii) Add 1cm depth NH3 (aq) to 1 cm depth FB8, then add excess NH3(aq) Blue solution formed

FB9 (i) Add 1cm depth NaOH(aq) to 1cm depth FB9, then add excess NaOH(aq) Pale green ppt formed, insol. in excess
(ii) Add 1cm depth NH3(aq) to 1 cm depth FB9, then add excess NH3(aq) Pale green ppt formed, insol. in excess

(The table above was really cramped for FB9, so I wrote legibly but very small.)

FB9
Explanation: Observations made match notes on chart.

Missed the last two parts of the question. How many marks out of 14-16 (the no. of marks it was worth) should I expect in this question?

increadable memory !!! what do u eat lol ??