-
We need your support!
We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
Search results
-
A level Biology: Post your doubts here!
It's active transport and therefore needs energy. Sorry for the wrong answer first :( -
A level Biology: Post your doubts here!
Active transport is when molecules that are small, but not lipid soluble go through the carrier proteins in the cell membrane. Bulk transport is when the membrane surrounds large molecules to big to go through the lipid bilayer, to form a vesicle inside which then travels through the cytoplasm. -
Chemistry and Physics AS paper 12 MCQS
thia question drove me crazy and the answer was so simple. Thank you mehranshaikh -
-
Chemistry and Physics AS paper 12 MCQS
since the C:H ratio is high, we can predict that benzene is present. Since it is not readily oxidised by mild oxidising agents, we say that it is a tertiary alcohol. draw the structures and the only compound which produced by the dehydration of X is D. -
Chemistry Electrolysis help!!
what sort of questions?- Aries_95
- Post #2
- Forum: O-Levels / GCSEs / IGCSE
-
Chemistry and Physics AS paper 12 MCQS
Look, since the C:H ratio is high, we can predict that benzene is present. Since it is not readily oxidised by mild oxidising agents, we say that it is a tertiary alcohol. draw the structures and the only compound which produced by the dehydration of X is D. -
Chemistry and Physics AS paper 12 MCQS
Can you plz mention the year and the question no plz! -
Chemistry and Physics AS paper 12 MCQS
For Q.9: For reaction 1: Kc=[X2Y]^2/[X2]^2[Y2] for reaction 2: Kc={[X2][Y2]^1/2}/[X2Y] =1/[{(X2Y)^2/(X2)^2(Y2)} the answer is A. -
Chemistry and Physics AS paper 12 MCQS
The question says that there are 0.02 moles of Al not Al2O3. My calculation: 4Al+3O2--->2Al2O3 AL2O3+6HCl---->2AlCl3 Since 4 moles of Al is equal to 2 moles of Al2O3, 0.02 moles of Al will be equal to 0.01 mole of Al2O3. According to equation, Moleos of HCl=6xmoles of Al2O3 i.e moles of... -
-
Chemistry and Physics AS paper 12 MCQS
Yaar I am not sure about 27. I mean i get confused between C and D. Let me work it out and then i'll tell you too :) -
P1 MCQ's preparation thread for chemistry ONLY!!!!
For Q.7: Helium is monoatomic while hydrogen is diatomic hence Helium behaves more like an ideal gas. THe answer is therefore B. Q.15: Al atom in AlCl3 has an incomplete octet. you can check by drawing the ddot cross diagram of AlCl3. to complete the octet, the reaction takes place. hence the... -
Chemistry and Physics AS paper 12 MCQS
For Q.23: D cannot be obtained when we heat pentane. the other options include CH4, C2H6 and C4H8 all of which can be obtained by heating pentane (Hope you have read about cracking before). Hence D will not be collected in the inverting tube. For Q.30: C6H12O is an aldehyde. when it is oxidised... -
Chemistry and Physics AS paper 12 MCQS
It's ok :) No, draw the isomer for the third compound, it is optical as well. NaBH4 is only a reducing agent thus won't add hydrogen to a double bond. For Q.39: Yes since H2SO4 is also a reducing agent, aldehyde is produced. since it is oxidised, the color of KMNO4 changes from purple to... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
For Q.22: Oxidation with cold KMNO4 produces diole is -OH will be attatched to both sides while in the polymer, only one side has OH attatched to it. In C we first polymerise 1,2-dichloroethene which is then hydrolysed and the -Cl is replaced by -OH. hence the answer is C. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
Yeah but we were talking about the effects of these conditions on products of oxidation of aldehydes :) -
Chemistry: Post your doubts here!
The answers are correct. Look again at the options, they are shuffled. the option C in s_O6 is option A in w_11 hence the answers are C and A respectively. -
Chemistry and Physics AS paper 12 MCQS
The answers are correct. Look again at the options, they are shuffled. the option C in s_O6 is option A in w_11 hence the answers are C and A respectively. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
I have notes for AS-Organic chemistry...here you go :) Hope they are helpful :) Yeah and do check out www.chemguide.co.uk It is a very helpful website.