From the previous post, we have started on our Mini Series on Tough MCQs.
Purpose is to enquire that students are exposed to tougher & tricky chemistry Multiple Choice Questions (Paper 1) that we have observed for the last 10 years.
How come i know them, you may asked? Cos i have been compiling and analyzing these questions for my students year-after-year, and sharing with them to ensure that they know how to avoid the common mistakes and traps that many other students have fallen into.
You know what – Usually this “tough” questions are Application Type Questions that just need a cool head and good chemistry concepts to get it right. It isnt that tough at all.
Let’s continue with more questions below:
Question 1:
Why is Sodium classified as Metal?
a) It is a pure substance
b) It is a good conductor of electricity
c) It exists as atoms, not molecules
d) It is very soft
Question 2:
Buckminsterfullerene was discovered in 1985 and it has a perfect sphere with formula C60. From this information, what can you deduce about it?
a) It contains only one element
b) It is a compound of 60 elements
c) It is a mixture of 60 atoms
d) It is a mixture of 60 elements
Question 3:
When mercury is heated, it forms mercury and oxygen,Mercury oxide (s) –> mercury (l) + oxygen (g)
What can you deduce from the above information?
a) During the heating of mercury oxide, all three states of matter exist
b) Mercury oxide is a mixture
c) Mercury oxide is a silver solid
d) The composition of mercury oxide varies during heating
PS: Try out the questions and enter your suggested answers (and comments) right below, so that others can come in to share their answers and thought process.
I’m guessing the answer is B, A, A respectively.
The most common property among metals is their ability to conduct electricity. the other answers have no relevance to identifying metals.
The formula of buckminsterfullerene is C60, hence it’s made of only one element because its formula has only one alphabet (C).
The first answer for question 3 makes the most sense because you can’t really deduce the other answers based on what the question has given. Furthermore, they gave us the state symbols so I’m guessing this question is really testing on your ability to pick out the information that it gives.
Reply
sean Reply:
November 9th, 2008 at 4:19 pm
Hi Sadiqin,
Well done! I am glad you took the actions and participate towards your own learnings.
Answers for the above questions are indeed B, A and A.
My thoughts are:
Question 1:
One of the common properties for Metals are indeed their ability to conduct electricity.
Question 2:
Good grasp of concepts. We can identiify the number of elements in a substance by looking at their chemical formula. In this case, we only see C thus it is an element. Other examples are Ozone (O3) and naturally occuring sulphur (as in S8).
Question 3:
Clever use of information in question. Since they asked what can be deduced from information given, it is important to realise you should only use information you see in the question. In this case, A would be the only logical answer based on what is given, which is the state symbols.
Keep up the good work.
PS: Are you based in Singapore taking your O Levels now?
To Your Academic Success in Chemistry,
Sean
Reply
Yup I’m based in Singapore, and I’m taking my Os now. The questions have indeed helped me exercise my rusty Chemistry skills after having had to study for other subjects since Chemistry paper 2.
Reply
sean Reply:
November 10th, 2008 at 11:53 am
Hi Sadiqin,
I am glad this chemistry blogsite and the questions discussed have helped you in your revision for O Level Chemistry.
Remember to use “chemistry concepts” & “instruction given in exams questions” to choose your final answer for MCQs.
Elimination Process is highly recommended.
All the Best to your Academic Success in Chemistry,
Sean
Reply
1) b
2) a
3) a
this is my attempt. hope i satisfy the passing mark………. inform me of my progress soon Sean. Thanks……
Reply
sir please upload mcqs from chapter 6 of o level book ‘Chemical bonding.i will be very thankful to you!!!
Reply