OCR B (Salters) F332 Tuesday 4th June 2013 Exam Discussion (Now Closed)

Oh the hydrogen has a delta + and is attracted to the lone pair on oxygen.

Thanks

Btw it says in the spec that we have to know about batch and continuous production, but it had not come up on past papers. What do they want us to know about it an what even is batch and continuous? Advantages and disadvantages o each method?

Thanks

Oh the hydrogen has a delta + and is attracted to the lone pair on oxygen.

Thanks

Btw it says in the spec that we have to know about batch and continuous production, but it had not come up on past papers. What do they want us to know about it an what even is batch and continuous? Advantages and disadvantages o each method?

Thanks

oh my god! thanks for reminding me of that I had to go over the chapter on green chemistry. Yep just basic disadvantages and advantages.

What's on green chemistry chapter, just batch vs continuous?

stuff like plant location, costs and efficiency, and waste disposal.

But there's no past paper questions on that chapter.

But there's no past paper questions on that chapter.

Say if they say describe how hydrogen bonds form. Is this okay

Lone pair on oxygen attracted to hydrogen with a delta + charge.

I don't get what attracts what. Does the oxygen attract hydrogen? Or does the hydrogen attract oxygen? Or does hydrogen attract the lone pair on oxygen? Or what?


Thanks

I would rather drink HCl than do this exam - revision for it seems endless!

Yeah that might have been a slight exaggeration... but this past year has made me absolutely despise chemistry to be honest and I can't wait for this exam to be over - it's the one I've been dreading the most and it's far too soon for my liking!

It is hard, but it will be over very soon now. And I'm sure you'll do amazingly!

hey guys, really dreading this exam as i gather most of you are -_-
can someone please help me on a q from the jan 2010 paper?
here's the question:

1f. Scientists monitor the composition of the Earth's atmosphere. They have found that the concentration of carbon dioxide in dry, unpolluted tropospheric air has increased from 300ppm to around 380ppm between 1900 and the present day.
i) Taking the present day value to be 380ppm, calculate the increase in the percentage of carbon dioxide in the air between 1900 and the present day.

I converted the values into percentages so,
380/100000=0.0038% and 300/100000=0.0030%
so the difference between these values is 0.008, therefore 0.008/0.003

but according to the mark scheme its meant to be 0.008/8*10^ -3.
Any help would be appreciated, its only one mark but its really frustrating me. Thanks in advance

It's summed up nicely on page 72 of the CGP revision guide

It's not just oxygen; it could be nitrogen, oxygen or flourine.

Yeah that might have been a slight exaggeration... but this past year has made me absolutely despise chemistry to be honest and I can't wait for this exam to be over - it's the one I've been dreading the most and it's far too soon for my liking!

Aw thank you, I hope so and I'm sure you will too I'm just annoyed with myself because I made quite a few stupid mistakes in unit 1 when it was actually a decent paper so now I have to really make sure I don't mess this exam up! I wish there was an equal split between unit 1 and 2, it's a pain to have so much more to remember for this exam (especially when I find most of it so boring!) But you're right, the exam may be very soon but that also means it will be over very soon!