Multiple Choice (2 Viewers)

[BadMeetsEvil]

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:
View attachment 23495

okay I get it now and I apologise for my false argument. but, the question asked for the decreasing of electrochemical activity which means the more negative should be first and the more positive is last.
anyways... I'm gonna start studying for physics now. Chem is done and nothing can be changed.

 

[zhuang281]

Same lol, gotta get through the option module for Phys. My argument was mainly influenced by the fact that the numero uno in my school (Ranked top 10) put D. What did you put anyway Khorne?

 

[khorne]

okay I get it now and I apologise for my false argument. but, the question asked for the decreasing of electrochemical activity which means the more negative should be first and the more positive is last.
anyways... I'm gonna start studying for physics now. Chem is done and nothing can be changed.

YOu are right, all the samples were metals, reactivity of oxidation/reduction can't be compared at the same time, otherwise simultaneously two metals would be stronger than eachother

 

[Tasha270494]

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

 

[khorne]

Haha. Well, imo I think I'm wrong (cause I did put C) - 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

If it does, then complain to the board...it's not defined in the syllabus. The only definition is explain reactivity in terms of substitutions in reactions.

 

[khorne]

If it does, then complain to the board...it's not defined in the syllabus. The only definition is explain reactivity in terms of substitutions in reactions.

I think we can settle this with:

#explain the displacement of metals from solution in terms of transfer of electrons
#identify the relationship between displacement of metal ions in solution by other metals to the relative activity of metals

Direct from the syllabus.

Also palladium (Pd) is a platinum group metal iirc (used in catalyst filters)...that makes it...really inert.

 

[Richard Llyod]

I think we can settle this with:

#explain the displacement of metals from solution in terms of transfer of electrons
#identify the relationship between displacement of metal ions in solution by other metals to the relative activity of metals

Direct from the syllabus.

Hey khorne you lanky man in a suit too big for you, you better state rank or benny lava will come after you

 

[weber]

1.A ethene+water->ethanol
2.D glucose->2ethanol+2co2
3.C vinegar, lemonade, lemon juice are acidic
4.D CFC
5.B not much to explain
6.A Simplest way to distinguish different mass on alkanols
7.B lead-207, calcium-40 are stable
8.C alkyl comes from alkanol, alkanoate comes from alkanoic acid
9.A polar dissolves polar
10.C HCl does nothing, Ag+ reacts with all, Ba2+ reacts with SO4 and CO3
11.D halogenation: adds both halogens into ethene
12.D reduction potential (increasing): Pd,Ag,Ni,Cd (can figure out .8V from table, Ag has low reactivity, therefore chemical activity is oxidation potential, reverse order for decreasing)
13.C solid does not contribute to equilibrium
14.C there is 5, go count
15.A weak acids completely ionise in alkaline conditions, same amount of H+ ions as strong acid
16.B strong base+strong/weak acid->neutral/basic salt respectively
17.D }
18.A }not doing calculations
19.B }
20.B 200g for first reaction, 200g for second reaction

 

[Prussan]

I don't suppose that anyone noticed that Q6 mentioned aluminium sulfate, except that sulfate was spelt sulphate...

There has been some debate and protest about the spelling of the word ‘sulphur’ and the apparent trend to spell it as ‘sulfur’. The debate and protest is not confined to Australia and is going on in many countries. Note too that in some countries ‘phosphorus’ can be spelled ‘fosforus'.

Much of the variation in spelling arises from scientific spelling as opposed to usage in day to day literature. About 20 years ago, the International Union of Pure and Applied Chemistry (IUPAC), the equivalent of a ‘United Nations’ of world chemistry, and other scientific organisations adopted the ‘sulfur’ form. For scientific correctness, most scientists have followed this form. The Australian journals of science have also adopted this spelling.

From CSIRO

 

[BadMeetsEvil]

1.A ethene+water->ethanol
2.D glucose->2ethanol+2co2
3.C vinegar, lemonade, lemon juice are acidic
4.D CFC
5.B not much to explain
6.A Simplest way to distinguish different mass on alkanols
7.B lead-207, calcium-40 are stable
8.C alkyl comes from alkanol, alkanoate comes from alkanoic acid
9.A polar dissolves polar
10.C HCl does nothing, Ag+ reacts with all, Ba2+ reacts with SO4 and CO3
11.D halogenation: adds both halogens into ethene
12.D reduction potential (increasing): Pd,Ag,Ni,Cd (can figure out .8V from table, Ag has low reactivity, therefore chemical activity is oxidation potential, reverse order for decreasing)
13.C solid does not contribute to equilibrium
14.C there is 5, go count
15.A weak acids completely ionise in alkaline conditions, same amount of H+ ions as strong acid
16.B strong base+strong/weak acid->neutral/basic salt respectively
17.D }
18.A }not doing calculations
19.B }
20.B 200g for first reaction, 200g for second reaction

GG!!! 17/20... Could've easily gotten 19/20.stupid mistakes from 1 and 14

 

[Gangstar1]

lost two marks in mc due to silly mistakes Q.Q

 

[utanobeiiby]

Look guys they term ELECTROCHEMICAL ACTIVITY doesn't even exist in scientific dictionary and the exam this year have added a whole load of ambiguous terms like that... so i wont try to guess what the EXAM WRITERS meant cause they seriously need to RELEARN ENGLISH!!