Predictions for Chemistry 2014 HSC? (1 Viewer)

[GOsie]

A. Bcoz side with more moles = more collisions = greater rate .

I would have thought B, because if equilibrium position is shifted to the RHS, more 'C' is forming which I think is shown in answer B

 

[photastic]

Just confirmed that the 11 year old will state rank chemistry

 

[Queenroot]

What HSC paper is it from? I'd go with B.

 

[iStudent]

A
rate of forward reaction is greater than rate of reverse reaction at any moment. Only A satisfies this condition.

 

[QZP]

I would have thought B, because if equilibrium position is shifted to the RHS, more 'C' is forming which I think is shown in answer B

Nope. If its shifting to the right that means rate of forward > rate of backwards. Hence A

 

[Cleverusername5321]

What HSC paper is it from? I'd go with B.

Trial that was used in my school in 2010.

 

[GOsie]

Nope. If its shifting to the right that means rate of forward > rate of backwards. Hence A

it doesn't necessarily start in the middle does it? In (A) the rate of the forward reaction gets slower. In (B) the rate of the forward reaction gets faster. Or is this still wrong?

 

[Queenroot]

Nope. If its shifting to the right that means rate of forward > rate of backwards. Hence A

Hahaha fuck didn't even look at the equations on the graph properly, you are right.
Reactants would be increasing and products would be decreasing.

 

[GOsie]

Nope. If its shifting to the right that means rate of forward > rate of backwards. Hence A

it doesn't necessarily start in the middle does it? In (A) the rate of the forward reaction gets slower. In (B) the rate of the forward reaction gets faster. Or is this still wrong?

Nvm I realised what I did wrong. I think I get it now. Thanks

 

[Cleverusername5321]

What about this? Aren't nitrous, ethanoic and sulfurous acids all weak, leaving only water? But water is water?

 

[GOsie]

What about this? Aren't nitrous, ethanoic and sulfurous acids all weak, leaving only water? But water is water?

Yeah I think there may be a typo in the question. What paper is this from?

 

[someth1ng]

What about this? Aren't nitrous, ethanoic and sulfurous acids all weak, leaving only water? But water is water?

All options are wrong.

 

[SuchSmallHands]

All options are wrong.

The hydronium ion is a strong acid, wouldn't it's conjugate base be OH-? (not sure, but it's the option I'd choose)

 

[Queenroot]

The hydronium ion is a strong acid, wouldn't it's conjugate base be OH-? (not sure, but it's the option I'd choose)

Hydronium ion's base is Water I believe

 

[SuchSmallHands]

Hydronium ion's base is Water I believe

Oops yeah, I think you're right.

 

[strawberrye]

The hydronium ion is a strong acid, wouldn't it's conjugate base be OH-? (not sure, but it's the option I'd choose)

Conjugate acids and bases really is a concept resulted from the Bronsted Lowry theory of classifying acids as proton donors and base as proton acceptors, as such, under this definition, acids and their corresponding conjugate bases often differ by a H+ proton, and thus, by this logic, conjugate base of hydronium ion would be water. Usually, the conjugate base of a strong acid is a weak base, and 0H- is a very strong base, so it would be highly unusual for it to be a conjugate base of a strong acid (I don't really think it is possible either).

 

[Cleverusername5321]

All options are wrong.

I was thinking. Could OH- perhaps be it, with something like NH3 + H2O --> NH4 + OH- ?

 

[GOsie]

Wouldn't it be D cause sulfuric acid has two dissociations:
H2S04 --> HSO3- + H+
and HSO3- <--> SO4(2-) + H+

first equation doesn't balance

 

[strawberrye]

What's not balanced in the equation?

Notice there are 4 oxygen ions in the left hand side, but only 3 on the right hand side.

Just in case some people may have missed my thread, I have posted a full trial HSC chemistry paper on this thread-the answers are also on this thread-these questions represents some of my predictions of potential HSC questions this year. So if you are bored of doing past papers and would like a challenge, feel free to download the paper and have a go under timed exam conditions

http://community.boredofstudies.org...a-library-hsc-chemistry-trial-discussion.html

 

[Cleverusername5321]

Notice there are 4 oxygen ions in the left hand side, but only 3 on the right hand side.

Just in case some people may have missed my thread, I have posted a full trial HSC chemistry paper on this thread-the answers are also on this thread-these questions represents some of my predictions of potential HSC questions this year. So if you are bored of doing past papers and would like a challenge, feel free to download the paper and have a go under timed exam conditions

http://community.boredofstudies.org...a-library-hsc-chemistry-trial-discussion.html

I looked at your paper. You posted your answer to question 4 as D. Shouldn't it be B? In fact, I'm certain that it should be B. D accounts for sulfate only, whereas the question is asking "What mass of barium sulfate precipitate would be expected to be formed.."