2009 GCE ‘O’ Levels Examinations will start in few days time. If you are a student based in Singapore, you must be excited it.
Hope you are revising well for Chemistry Exams. In any case that you would like more challenging exam-based questions to discuss – check out the following questions on Salts!
Question 1:
Which of the following salts cannot be prepared by reacting a metal with a dilute acid?A. copper(II) chloride
B. iron (II) chloride
C. magnesium sulfate
D. zinc sulfate
&
Question 2:
Which one of the following pairs consists of substances that produce a precipitate when their aqueous solutions are mixed?A. sodium nitrate, barium chloride
B. sodium nitrate, silver sulfate
C. sodium sulfate, barium chloride
D. sodium chloride, barium nitrate
&
Question 3:
The reaction represented by the ionic equation:Ba2+(aq) + SO42-(aq) –> BaSO4(s)
takes place readily when:
A. aqueous barium nitrate is added to aqueous sodium sulfate
B. molten barium sulfate is cooled until it solidifies
C. solid barium chloride is added to dilute sulfuric acid
D. solid barium sulfate is heated until it melts
All the best to your final revision for ‘O’ Level Chemistry Exams!
PS: I would love to hear from you on your preparation towards the exams. Hope this website helps you all this while.
Cheers,
Sean =)
Qn1.A Reason:Copper is not a reactive metal
Qn2.C Reason:Test for sulfate ion
Qn3.A Reason:Two soluble solution to make up a insoluble salt(precipitation)
May I ask if my explanation is right?
thanks 🙂
Hi JM,
I love the way you explained it.
Your answers are spot on!
Keep up the good work,
Sean
Hi Samiha,
Answer for Question 2 is (C) as suggested by JM above.
The products of that mixing gives you Sodium chloride (soluble) + barium sulfate (insoluble/ppt).
Please note that your choice is incorrect since Barium Chloride is soluble in water.
Hope this helps.
wats da ryt answer for Q2 ??? :S D or C n why?? :S
Q1. A (copper does not react with dilute acids)
Q2. D (white ppt of barium chloride formed)
Q3. A ( the reaction shows dat barium is in (aq) state wheres options C and D shows barium is solid. in B, the BaSO4 is already a compound)
Q1: A
Copper is non-reactive metal
Q2: C
Product = Sodium chloride (soluble) + barium sulfate (insoluble/ppt)
Q3: A
The question speaks for itself… 🙂 for those who are unsure, its the precipitation method for the preparation of insoluble salts