Chemistry MCQ's help!

[scouserlfc]

Are u sure yaar that in Q1 u gave the options are correct like the u gave the numbers correct because every grp 1 element almost reacts with water violently.And yeah they always form hydroxide so when they form hydroxides they make bases and bases are always above 7 in Ph.

Could u also tell the years of these questions.

 

[bikermicefrmars]

@scouserlfc....soory I dont know the years But most probably it is from 2005 paper!

And can u answer this:

The relative atomic mass of oxygen is 16.
What are possible values of the relative molecular mass of different molecules of water formed by
the combination of oxygen and hydrogen?
1 18
2 19
3 20
A 1 only
B 1 and 2 only
C 1 and 3 only
D 1, 2 and 3

I think it;s D becoz in marking scheme it was D,...whatdya think?

 

[abcde]

It is definitely D. I mentioned before

 

[bikermicefrmars]

Thanks and sorry for overlooking it?!!

 

[abcde]

you're welcome

 

[scouserlfc]

well u both goin to give chem in cie this year right/

 

[abcde]

yes for me, dunno about bikermicefrmars...

 

[bikermicefrmars]

@scouserlfc.....not me I will only be giving Pakistan Studies and Islamiyat

 

[scouserlfc]

i the same as u @bikermicefrmars well gud luck abcde in chem exam.

 

[joelynn]

how to do no. 11 paper 1 june 2004 for 9701 chem??

 

[abcde]

how to do no. 11 paper 1 june 2004 for 9701 chem??

Can you please post the link here?

 

[leosco1995]

Here.

Also, it's an A-level question, most of us here are O-level students so you should post your A-level queries here.

Also, can someone please help me with MCQs 14, 31 and 36 in this paper?

 

[abcde]

Here.

Also, it's an A-level question, most of us here are O-level students so you should post your A-level queries here.

Also, can someone please help me with MCQs 14, 31 and 36 in this paper?

AOA, leosco!
For 14: In an electric cell/simple cell, electrons flow from the more reactive metal to the less reactive metal so X has to be more reactive than Y and Y has to be more reactive than Z. Thus the answer would be D (using the reactivity series).
For 31: The table shows a constant change in heat of combustion between any two nearest alcohols. 1380 - 750 = 2010 - 1380 = 2640 - 2010 = 630 kJ/mol.
Now find the difference between your required alcohol's heat of combustion and that of butanol. It's 3900 - 2640 = 1260. This is double the change between two nearest alcohols! So the required alcohol would have 2 more carbon atoms, that is, 4 + 2 = 6. As for hydrogen atoms, they would be 2(6) + 1 + 1 =14 using the general formula so its D. I'm not good at explaining but hope you get my point.
For 36: Only unsaturated vegetable oils react with hydrogen and when they do so, obviously they'll use up at least some the hydrogen provided as reactant. So if the volume of hydrogen has decreased at the end of the reaction, it's a sure sign a reaction has occured. This happens when Q, R and S are used so the answer is C.
Hope you understand.

 

[leosco1995]

WS!

I understand all of them now, thanks. I also learnt some new stuff there.

 

[abcde]

Good to know. Best of luck!

 

[iFuz]

=)

 

[milkboyz]

Anyone explain these two questions to me please? Thanks first! :Yahoo!:
FYI, the answer given for Q10 is D whereas for Q11 is D.

 

[purplishgirl]

Re: Physics help!

Some1 help me!!! i cant find physics 2010 marking scheme...
i nyd it as soon as possible :'(

 

[abcde]

Re: Physics help!

Some1 help me!!! i cant find physics 2010 marking scheme...
i nyd it as soon as possible :'(

Dear purplishgirl, your desired mark scheme would be here.

 

[Arish Yaseen]

This one as well:
Q What is the mass of aluminium in 204 g of aluminium oxide, Al2O3?
A 26 g B 27 g C 54 g D 108 g

Answer: D

And this one:
Q Hydrogen can form both ionic and covalent compounds.
With which element will hydrogen form an ionic compound?
A carbon
B chlorine
C nitrogen
D sodium

Answer

And from which chaps are these questions?

ANSWER Q2: B forms HCl an ionic compound