Omg, chemistry paper 1 is next week and i really need help with some of these tyrant questions!!!!!

[farahroslend]

Stressed man!!!!!!! So frustrating! How can we get the answers for these questions? Question 13. (B) 18. (A) 21. (C) 30. (B) and 34. (B)
From this past years papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s05_qp_1.pdf


Please explain with as much detail as possible.. And why is 21. Not nucleophilic substitution?

I know im supposed to be patient and calm, but THIS IS REALLY GETTING TO ME!!!!!!! Graaaaaaahhh. Sorry.
Especially when i have no one to refer to!!!! Im on holiday. Ohhh yea. Oh yes!!!!!!!!!
Thank you for your help... Really. Thanks

Also do the past years get harder every year or is the standard maintained?

 

[h4rriet]

Stressed man!!!!!!! So frustrating! How can we get the answers for these questions? Question 13. (B) 18. (A) 21. (C) 30. (B) and 34. (B)
From this past years papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_s05_qp_1.pdf


Please explain with as much detail as possible.. And why is 21. Not nucleophilic substitution?

I know im supposed to be patient and calm, but THIS IS REALLY GETTING TO ME!!!!!!! Graaaaaaahhh. Sorry.
Especially when i have no one to refer to!!!! Im on holiday. Ohhh yea. Oh yes!!!!!!!!!
Thank you for your help... Really. Thanks

Also do the past years get harder every year or is the standard maintained?

For 13 you have to know that metals at the top of Groups are similar chemically to metals at the top of adjacent Groups.
18. There's no bi-product, so the elements is ammonium cyanate = the elements in urea, including the numbers.
21. Nucleophilic substitution happens when a nucleophile attacks a polar bond. There's no polar bond here being attacked.
30. That's something you just have to memorise.
34. Use Le Chatelier's principle to reason the answers.