06 Oct
Posted by: sean in: Chemistry Notes & Tips
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Question from a Top School 2007 O Level Chemistry Prelim Paper:
Question:
Astatine is a Group VII element below Iodine in Periodic Table. Which of the following statements concerning Astatine is correct?
A) It is a liquid at room temp and pressure.
B) It is a stronger oxidizing agent than iodine
C) It reacts with sodium ti form an ionic compound
D) Its diatomic molecules are held together by weak covalent bonds
Should be a manageable question. Enjoy doing!
PS: Leave your suggested answers in the “Comments” section below.
Rgds
Sean
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3 Responses
lijun(:
07|Oct|2007 1i think the answer is C.
since it’s below iodine, it should be a solid at rtp. so it can’t be A.
also, the higher the halogen in the group, the more reactive it is. so iodine should be a stronger oxidizing agent than astatine. so it’s not B.
it’s diatomic molecules are held together by weak van der waals forces, not weak covalent bonds. thus not D.
since it’s in group VII, its ion has a charge of -1. thus will form ionic compound with sodium, which has a charge of +1. forming NaAt.
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Anonymous
07|Oct|2007 2C. Sodium is a metal and astatine is a non metal (under halogens group) so they go through ionic bonding to form ionic compounds.
I’m not sure about A, so I left it out first.
B)Iodine is more reactive than Astatine, this makes it a stronger oxidising agent. I’m not sure whether this theory is right.
D)It is a diatomic molecule, but covalent bonds are strong. It’s the intermolecular forces of attraction that are weak.
So by comparison, C sounds like a more logical answer than A. Do correct me if I’m wrong though.
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Sean Chua
09|Oct|2007 3Well Done Lijun and Anonymous.
Answer is indeed C.
Keep up the good work!
Chem Prac in two days time.
All the Best!
Rgds
Sean
SimpleChemConcepts
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