As is usual at this time of year, upon the publishing of the official scoring standards I make VERY minor adjustments to my previous years worked answers. The following list is a summary of the trivial changes that have been made, ALL of the chemistry was 100% correct the first time!

Question 1:

I speculated that part (d) would be worth 2 points, it was actually worth 1.

Question 2:

I removed a significant figure typo from one of the numbers in the calculation in part (e).

Question 3:

I speculated that part (c) would be worth 2 points, it was actually worth 1.

I speculated that part (d) would be worth 3 points, it was actually worth 2.

I added a phrase at the bottom of part (f).

Question 4:

No changes. 

Question 5:

I speculated that part (a) would be worth 2 points, it was actually worth 1.

(As an aside, I feel that this question SHOULD be out of 2 points with one point awarded for the use of state symbols, since the definition INCLUDES a reference to states).

I speculated that part (b) would be worth 2 points, it was actually worth 1.

I speculated that part (c) would be worth 2 points, it was actually worth 1.

QUESTION 6:

No changes.

All adjusted materials have been updated in the relevant subscriber areas.