If sulfates are soluable then how.......

[arabiannight975]

http://www.xtremepapers.net/CIE/index.p ... _qp_11.pdf

Question no 2
It says that they are trying to obtain Magnesium sulfate crystals...
now all sulfates are soluable so now after he mixes both the things it will still be a liquid and he would have you either evaporate it or crystalize it..
No solids will be formed in the soultion so why is it filterring it????

plz explain!


and question nmbr 23

can anyone tell me why doest Cu reacts with dilute acids?? and which other elements does not???

 

[Saturation]

QS 2
You missed the last part! : "He adds magnesium carbonate until no more reacts."!
Which means he'll have to first FILTER the excess! Then he'll carry out evaporation and crystallization! So it will be "C"

QS 23
Copper is a very unreactive metal. It' won't react with acids since it's below Hydrogen in the reactivity series. All metals below copper, such as Silver, Gold and Platinum don't react with dilute acid.

Here you go:
http://en.wikipedia.org/wiki/Reactivity_series

Hope that helped! :mrgreen:

 

[XPFMember]

Reaction may be too violent so remember only MAZIT metals react with acid MAZIT => M-magnesium , A-aluminium , Z-zinc , I-iron , T-tin

 

[arabiannight975]

Thnx both of you..
That helped a lot.!!


and ya does anyone of you happens to have a like SHORT FORM of the reactivity .......
I wanna learn it but WITH CARBON and HYDROGEN included.!
so plz let me know how to learn it by heart!

 

[exampasser]

Just make a sentence which you can remember!

Mine (with hydrogen and carbon) is:

Prashant (any name beginning with P) Says Coke Makes A Crazy Zambian in Thailand Live Happily Cos Music Sales Go Platinum

Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Tin, Lead, Hydrogen, Copper, Mercury, Silver, Gold, Platinum.

I didn't even have the "crazy" part there before. I just added it now! It's that easy. If you make a sentence make sure it's CRAZY so you can remember it