Recent content by Tasha270494

Bachelor Science (major in Vision Science)/Bachelor of Optometry

HEY! I got into optom at unsw tooo ! highfive. :D

Haha. Well, imo I think I'm wrong (cause I did put D) - and I'm pretty sure electrochemical activity refers to reducing/oxidising ability. And Ag's ability to reduce is greater than Cd's/Ni's ability to oxidise.. But if you guys are right - awesome :)

lol. This is harder to explain than I thought.. Electrochemical activity refers to the oxidising/reducing power. Activity series is only metals and thus your only taking into consideration the ability for it to oxidise and lose electrons. Look at the image:

.. never saw it in textbooks either. But activity series is different to electrochemical series: "E° values give you a way of comparing the positions of equilibrium when these elements lose electrons to form ions in solution. The more negative the E° value, the further the equilibrium lies...

... you know what I meant. Anyways, its okay if you don't agree (:

? I'm pretty sure it is B (even though I put C) You can see that Pd wants to give away electrons (reduce) moreso than Cd2+ gaining electrons (oxidise) since it requires a higher voltage - more likely to occur.

YEP. Everyone got Q.12 wrong - it is in fact B Electrochemical activity includes both the ability to oxidise or reduce and therefore you havto take the absolute value and then rank it.

Yeah. They usually repeat questions that weren't answered well in the past..

+ 1

Arrhenius' theory is useful because it explains acidic/basic behaviour really well in aqueous media. The theory says that acids in aqueous media produce H+ whereas bases produce OH- ions. It clearly explains neutralisation reactions, where equal amounts of H+ and OH- when combined produce water...

Yeah.. I said that too - but what if it was a strong diprotic acid? Would that still produce the same amount of energy release as a monoprotic acid - why?

I'm pretty sure it's all right except.. 12 - D (decreasing order) 13 - C (solid doesn't affect equilibrium) 15 - C

did anyone get the "why is it that a strong base and strong acid always produce -57Kj/mol when neutralised?"

..no maybe if you ring board of studies.