Chem QA

Jasmine ngjiamin SG

Pale green solution A---------- (excess aq NH3)----------> Green ppt------(expose to air warming)------------> Red brown ppt C

What is A and C?

Then,

Red Brown ppt C------(solution PH1)-------> Yellow/brown solution B----(bubble SO2)----->A

What is B?

UltimaOnline SG

Pale green solution A---------- (excess aq NH3)----------> Green ppt------(expose to air warming)------------> Red brown ppt C

What is A and C?

Then,

Red Brown ppt C------(solution PH1)-------> Yellow/brown solution B----(bubble SO2)----->A

What is B?

A is Fe2+ (aq)

C is Fe(OH)3 (s)

B is any soluble Fe3+ salt, eg. Fe2(SO4)3(aq) or Fe(NO3)3(aq) or FeCl3(aq).

Jasmine ngjiamin SG

OK thks alot!

UltimaOnline SG

OK thks alot!

No problem, Jasmine.

Remember to plan ahead beyond 'O' levels. Eg, if you want to do engineering in the Uni, be sure you take H2 Physics and H2 Maths in JC. If you want to do Life Sciences in the Uni, be sure you take H2 Chemistry and H2 Biology in JC. And so on.

See the NUS list of prerequisite subjects :
click on 'A' level and Mature applicants (with H1/H2 results)
http://www.nus.edu.sg/oam/apply/local/prerequisites/BYA-prerequisites.html