ExamPro Chemistry Unit 3/4 Study Guide - ERRATA

[thushan]

Please post in this thread if you think there is an error. I will write a summary of all the errata on this post.

If it says 'fixed for next print run' it means that the next print run of books will not have these errors since I have fixed them. I will post when this occurs. At the moment, a new book you will buy will still contain these errata.

BOOK 1: Topic Tests and Trial Examinations

Unit 3 AOS 2 Test 3 - Biochemistry, Q4c. (page 63)
The question currently reads "What is the name of the linkage that joins two DNA molecules together?"
It should read "What is the name of the linkage that joins two DNA nucleotides together?"
Fixed for next print run.


Unit 4 AOS 1 Test 2 - Equilibria, Q5dii. (page 84)
The question should read -
Use your answers to parts a, c and di. to derive a general equation relating K_a, K_b and K_w.
Fixed for next print run.


Unit 4 AOS 1 Test 2 - Equilibria, Q5diii. (page 85)
The question should read -
The value of K_w at 298 K can be found in the Data Book. Using your equation derived in part dii., determine K_b for this reaction at 298 K.
Fixed for next print run.


Unit 4 AOS 2 Test 2 - Electrochemistry, Q1d. (page 107)
In the third line, it currently reads "From this she correctly deduces that Li is stronger oxidant than K."
It should read "From this she correctly deduces that Li is a stronger reductant than K."

Fixed for next print run.


Exam 1 SAQ2n. (page 131)

The question currently reads:

"Use your answer to part f to determine the value of X, correct to 3 significant figures."

It should read:

"Use your answer to part m to determine the value of X, correct to 3 significant figures."

Fixed for next print run.


BOOK 2: Solution Manual

Model Solutions to Exam 1 SAQ2k. (page 80)


These currently read:

"One mark is awarded for any of the following assumptions:

• ionisation of hydrocyanic acid is negligible ([C₅H₁₀O₂] initially is equal to [C₅H₁₀O₂] at equilibrium)
• contribution to [H₃O⁺] from self-ionisation of water is negligible ([H₃O⁺]_eq = [C₅H₉O₂^-_eq])
• the amount of H₃O⁺ that reacts with the OH^- via the self-ionisation equilibrium of water is negligible"

It should read:

"One mark is awarded for any of the following assumptions:

• ionisation of hydrocyanic acid is negligible ([C₅H₁₀O₂] initially is equal to [C₅H₁₀O₂] at equilibrium)
• contribution to [H₃O⁺] from self-ionisation of water is negligible ([H₃O⁺]_eq = [C₅H₉O₂^-_eq])
• the amount of H₃O⁺ that reacts with the OH^- via the self-ionisation equilibrium of water is negligible"

Fixed for next print run.


Detailed Solutions to U3AOS2T2 (page 180)
The solution keeps making a reference to the mass of the compound being 1.42 g. However, it is actually 1.43 g.

Fixed for next print run.


Detailed Solutions to Trial Examination 1, MCQ 22 (page 271)
The last paragraph had a pretty embarrassing typo that I had not picked up until now. It initially reads 'thisisnot ascmmon'. It is meant to be 'this is not as common'.
Fixed for next print run.


Detailed Solutions to Exam 1 SAQ2h. (page 280)

At the bottom lines of the solution, it reads
"However, do not be misled into thinking that HCN simply decomposes to CN^- and H+."

It should read:

"However, do not be misled into thinking that C₅H₁₀O₂ simply decomposes to C₅H₉O₂ and H+."

Fixed for next print run.

Detailed Solutions to Exam 1 SAQ2j-k. (page 280)

After step 2) of the solution, a few lines below, it currently reads:

"To get around this problem we need to realise that the amount of H₃O⁺ produced from the self-ionisation of water is extremely small – only 0.0000001 M concentration. It will not even measurably add to the amount of H₃O⁺ produced from the reaction between cyanide ions and water. Therefore, we can ignore the H₃O⁺ ions from the self-ionisation of water. In the VCAA exam you can always make this assumption."

It should read:

"To get around this problem we need to realise that the amount of H₃O⁺ produced from the self-ionisation of water is extremely small – only 0.0000001 M concentration. It will not even measurably add to the amount of H₃O⁺ produced from the reaction between C₅H₉O₂^- ions and water. Therefore, we can ignore the H₃O⁺ ions from the self-ionisation of water. In the VCAA exam you can always make this assumption."

Fixed for next print run.

Detailed Solutions to Exam 1 SAQ2n. (page 282)

The first part of the solution reads currently:

"This question requires some ingenuity.
We need to basically find the maximum possible percentage ionisation. Now, the question stem tells us to use our answer to part f. In part f we determined..."

It should read:

"This question requires some ingenuity.
We need to basically find the maximum possible percentage ionisation. Now, the question stem tells us to use our answer to part m. In part m we determined..."

Fixed for next print run.

Detailed Solutions to Trial Examination 1, SAQ 3c. (page 284)
The third last line should read: "which means the enthalpy of the system after the reaction will be higher than that before the reaction".

Fixed for next print run.

Detailed Solutions to Exam 1 SAQ5c. (page 287)

The last line of the detailed solutions, which show the final oxidation half equation, show Cl^- as (aq). It should be (l).

Fixed for next print run.

[thushan]

An error has been posted into the original post, and has been replicated here for quick reference.

Book 1

Unit 4 AOS 2 Test 2 - Electrochemistry, Q1d. (page 107)
In the third line, it currently reads "From this she correctly deduces that Li is stronger oxidant than K."
It should read "From this she correctly deduces that Li is a stronger reductant than K."

[thushan]

An error has been posted into the original post, and has been replicated here for quick reference.

Book 1

Unit 3 AOS 2 Test 3 - Biochemistry, Q4c. (page 63)
The question currently reads "What is the name of the linkage that joins two DNA molecules together?"
It should read "What is the name of the linkage that joins two DNA nucleotides together?"

[thushan]

Another typo - put into original post as well:

Unit 4 AOS 1 Test 2 - Equilibria, Q5diii. (page 85)
The question should read -
The value of K_w at 298 K can be found in the Data Book. Using your equation derived in part dii., determine K_b for this reaction at 298 K.

[thushan]

Hey - sorry about that I should make that clearer actually. The next print run will occur when the current print run of books are sold out; I don't know when this will happen.

If you bought a book now, it will still have these errors because that's part of the current print run - sorry about that! But at least we've got them all documented in this thread here.

I'll edit the OP to explain what I meant by next print run.

[thushan]

Detailed Solutions to U3AOS2T2 (page 180)
The solution keeps making a reference to the mass of the compound being 1.42 g. However, it is actually 1.43 g.

Fixed for next print run.


Copied onto OP.

[thushan]

Detailed Solutions to Exam 1 SAQ3d. (page 284)

The third last line should read: "which means the enthalpy of the system after the reaction will be higher than that before the reaction"

Copied onto OP.

[speedy]

Not sure if it has already been fixed, but page 280 detailed solutions, last line of part h: shouldn't be HCN, should be for compound D. I don't think this has been picked up already but idk.

Edit: Cyanide was mentioned at the bottom of the page, and again on 281 in the second paragraph.
Also on page 80 under Part K.

Edit: Also, page 131 of questions, question n should refer to part m; same with on page 282 of the detailed solutions. This confused me so I left the question, in fairness, it was a tough question and probs wouldn't have gotten it anyway

Edit: Page 287 Detailed solutions, right at the bottom, 2Cl- should be (l)

[thushan]

Detailed Solutions to Exam 1 SAQ2h. (page 280)

At the bottom lines of the solution, it reads
"However, do not be misled into thinking that HCN simply decomposes to CN^- and
H+."

It should read:

"However, do not be misled into thinking that C₅H₁₀O₂ simply decomposes to C₅H₉O₂^- and H+."

[thushan]

Detailed Solutions to Exam 1 SAQ2j-k. (page 280)

After step 2) of the solution, a few lines below, it currently reads:

"To get around this problem we need to realise that the amount of H₃O⁺ produced from the self-ionisation of water is extremely small – only 0.0000001 M concentration. It will not even measurably add to the amount of H₃O⁺ produced from the reaction between cyanide ions and water. Therefore, we can ignore the H₃O⁺ ions from the self-ionisation of water. In the VCAA exam you can always make this assumption."

It should read:

"To get around this problem we need to realise that the amount of H₃O⁺ produced from the self-ionisation of water is extremely small – only 0.0000001 M concentration. It will not even measurably add to the amount of H₃O⁺ produced from the reaction between C₅H₉O₂^- ions and water. Therefore, we can ignore the H₃O⁺ ions from the self-ionisation of water. In the VCAA exam you can always make this assumption."

[thushan]

Model Solutions to Exam 1 SAQ2k. (page 80)


These currently read:

"One mark is awarded for any of the following assumptions:

• ionisation of hydrocyanic acid is negligible ([C₅H₁₀O₂] initially is equal to [C₅H₁₀O₂] at equilibrium)
• contribution to [H₃O⁺] from self-ionisation of water is negligible ([H₃O⁺]_eq = [C₅H₉O₂^-_eq])
• the amount of H₃O⁺ that reacts with the OH^- via the self-ionisation equilibrium of water is negligible"

It should read:

"One mark is awarded for any of the following assumptions:

• ionisation of hydrocyanic acid is negligible ([C₅H₁₀O₂] initially is equal to [C₅H₁₀O₂] at equilibrium)
• contribution to [H₃O⁺] from self-ionisation of water is negligible ([H₃O⁺]_eq = [C₅H₉O₂^-_eq])
• the amount of H₃O⁺ that reacts with the OH^- via the self-ionisation equilibrium of water is negligible"

[thushan]

Exam 1 SAQ2n. (page 131)

The question currently reads:

"Use your answer to part f to determine the value of X, correct to 3 significant figures."

It should read:

"Use your answer to part m to determine the value of X, correct to 3 significant figures."

[thushan]

Detailed Solutions to Exam 1 SAQ2n. (page 282)

The first part of the solution reads currently:

"This question requires some ingenuity.
We need to basically find the maximum possible percentage ionisation. Now, the question stem tells us to use our answer to part f. In part f we determined..."

It should read:

"This question requires some ingenuity.
We need to basically find the maximum possible percentage ionisation. Now, the question stem tells us to use our answer to part m. In part m we determined..."

[thushan]

Detailed Solutions to Exam 1 SAQ5c. (page 287)

The last line of the detailed solutions, which show the final oxidation half equation, show Cl^- as (aq). It should be (l).

[grannysmith]

Model Solutions to U3 AOS2 TEST 2 Q4b. (page 31)

It says the molecular formula is C₂H₆O when it's supposed to be C₂H₆O₂