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Chemistry and Physics AS paper 12 MCQS
Q9- only bonds are forming here. One X-X bond and 6 X-H bonds. so 6*395=2370 energy to form X-X + energy to form X-H = -2775 X-X - 2370=-2775 X-X=-405 Instead of - we put a + sign because they asked for bond energy and bond energy is always +ve according to its definition. so bond energy= +405... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
Q21- Substitute n by numbers 1 to 4. then find all isomers. There will be 7. Q37- In 2 there will be only one ketone and one acid as there is one primary and one secondary C atom. In 3 a ketone and a dibasic acid will b produced. Only one has 2 secondary C atoms so it will produce 2 ketones... -
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A level Biology: Post your doubts here!
Again this one is the best one according to me :) -
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Chemistry: Post your doubts here!
I studied from this textbook and it has all you need! I was able to study without a teacher as well and achieve a great score so i definitely recomment this textbook :) -
A level Biology: Post your doubts here!
Cambridge International AS and A Level Biology Coursebook (with CD-ROM) Third edition Author: Jones, M, Fosbery, R, Gregory, J, and Taylor, D -
AS Physics P1 MCQs Preparation Thread.
road has an upward force on wheel as it is the opposing force to the weight of the car so it is either A or B. The car moves towards the right so the road applies a force on the wheels to the right making it able to move so the answer is B. -
Chemistry: Post your doubts here!
Cambridge International AS and A Level Chemistry Coursebook with CD-ROM Author: Norris, R., Ryan, L. and Acaster, D. -
Chemistry: Post your doubts here!
May 2004 - Q1 - moles of hydrogen=mass/Mr = 1/2=0.5. *6.02*10^23 to find number of molecules. u get 3.01*10^23molecules. one molecule has 2 atoms so multiply by 2 u get 6.02*10^23 atoms. then find atoms in the options. neon is right as it is one mole and monatomic so it also has 6.02*10^23... -
Chemistry and Physics AS paper 12 MCQS
Q9- momentum=mass*velocity= 2mv if its elastic, momentum after collision will also be 2mv so the total collision would be 4mv. here its inelastic so it is not 4mv. Its not 2mv as well because this would mean it did not rebound. so it is 3mv Q14- find the component of the force. it will be... -
A level Biology: Post your doubts here!
yeah thats why TB is not the answer. It is infectious and doesnt have a vector so it can be transmitted. Question is which is NOT transmitted. chromosomes just condense and become visible in prophase and crossing over takes place, but the formation takes place in interphase -
A level Biology: Post your doubts here!
Q15- intracellular transport is transport within the cell and intercellular is transport between cells. Q19- chromosome formation is the replicaton of DNA and that happens in interphase not prophase. Q36- cholera is an infectious disease that can spread without a vector but mosquito is the... -
A level Biology: Post your doubts here!
it doesnt get disrupted by the casparian strip. appoplast pathway is pathway of water through non living parts. xylem is non living so it is appoplast pathway. fungi affect the xylem and so the appoplast pathway gets affected -
A level Biology: Post your doubts here!
Q30- fungi grows in the xyelm so water transport in xylem will be less efficient. Transport of water through xylem is appoplast pathway so appoplast pathway gets affected Q27- water transport in xylem depends on the force of cohesion which keeps the water molecules together and maintains a... -
A level Biology: Post your doubts here!
2 black shaded cells are the RBC's -
Chemistry: Post your doubts here!
Q6- find the mass of ice 1st using density=mass/volume. u get mass 1g. find moles of ice. 1/18=0.056 then V=nRT/P = 0.056*8.31*596/101000 = 0.00027m^3 then convert to dm^3 Q30- alcohol comes on the right side. In C also ethanol is at the right. X is oxidised into Y and Y reacts with alcohol... -
Chemistry and Physics AS paper 12 MCQS
Q1- 3*10^-21 * 6.02*10^23 = 1806 Q2- P in P2O5 = 62/62+80=0.43*30=13.1% Q3- C6H12 + 9O2 --> 6CO2 + 6H2O mass of water= 18*6=108 mass of CO2= 44*6=264 108/264=0.41 -
Chemistry: Post your doubts here!
there is no affect of the Cl-Cl bond or Br-Br bond here. The main bond here is H-Cl and H-Br. U should refer to there bonds to answer the question. Bond energies are diff according to the elements they are bonded to so we cant relate Cl-Cl and Br-Br to H-Cl and H-Br