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P1 MCQ's preparation thread for chemistry ONLY!!!!
But CIE meant the apparatus in Q.40 to be a reflux apparatus. You can tell it wasn't meant to be a distillation apparatus because none of the reactions 1/2/3 show a distillation reaction. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
12. The top of the curve becomes lower, so it can be either B or D. D's area is much less than the area of the first graph, so it's B. 18. In A & B, a co-ordinate covalent bond is set up between the lone pair and I and H. In D too a co-ordinate covalent bond is set up between the lone pair of... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
27. How can you get CH2BrCH2OH from CH2CH2? Electrophilic addition will yield CH2BrCH2Br. To get the CH2BrCH2OH, you'll need an additional step - nucleophilic substitution. A is wrong; both products are not obtained by electrophilic addition. 30. HCN won't reaction with the C=C double bond in... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
The apparatus for distillation and reflux is the same! -
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P1 MCQ's preparation thread for chemistry ONLY!!!!
Use p1v1+p2v2=p3v3. -
AS (Biology) P1 MCQs Preparation Thread.
20. 12000/2 because it's double-stranded. 6000/3 because 3 bases (and therefore 3 nucleotides) will code for 1 amino acid. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
1. Write a balanced equation and use the mole ratios. 13. The oxides of Period 3 elements get more acidic as you go across the period. 14. Sulphur dioxide in aqueous solution gives sulphite ions, and sulphur trioxide gives sulphate ions. -
AS (Biology) P1 MCQs Preparation Thread.
3. Cell 3 is a xylem vessel, therefore has to have a lower water potential than both 1 & 2. 13. The cell surface membrance doesn't 'allow for intracellular transport'; it allows for intercellular transport, i.e. transport of materials from cell to cell, not within the cell. Glycoproteins mainly... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
A benzene molecule is like this: . The Carbon atom you marked has a double-bond, therefore has only 3 groups attached to it & can't be chiral. It helps to remember that benzene isn't chiral, no matter which Carbon you refer to (they all have double-bonds anyway). -
AS (Biology) P1 MCQs Preparation Thread.
24. B & C can both be correct if you look at the first column only, but since there's also the second column to consider, you have to choose between the two. B can't be correct because hormone detectors are located on the cell surface membrane, therefore hormone detection has only to do with the... -
AS (Biology) P1 MCQs Preparation Thread.
36. No. The cholera bacteria is not trasmitted by air droplets; only the TB bacteria is. 31. Plasmodesmata is not a pathway. The symplast pathway includes the way through plasmodesmata. 14. C is wrong because R is the point of optimum activity. D is wrong; S is not the very end of the curve... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
The ox. no. of N in NO2 is +4. In HNO3, it's +5 and in HNO2, it's +3. It undergoes disproportionation. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
I opened the Physics paper, lol, sorry. Here's the answer to your question: P <-> Q + 2R Initial moles 2 0 0 (respectively) Change in moles -x +x +2x (respectively) Final moles 2-x x 2x (respectively) Add the final moles, and you'll get the number of moles they've given in the question. -
AS (Biology) P1 MCQs Preparation Thread.
37. Sickle cell anaemia is the genetically inherited condition, so the answers can only be either B or C. Cholera bacteria invade gut cells, so the answer is C. 36. Cholera and TB are both infectious and bacterial. A shows this. 31. Because the apoplast pathways gets blocked by suberin, water... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
The area of a v/t graph is the displacement; the 1st half of the wave is positive displacement, the 2nd half is negative displacement. Since the positive and negative displacements are the same, the overall displacement is zero. At 1/2T, the displacement is maximum; in B, C & D, the... -
AS (Biology) P1 MCQs Preparation Thread.
Variant 12, I presume: 37. Cholera is spread via contaminated food and water. 36. Not TB, so not D; not cholera, so not A & B; so C. 31. C; it's a fact. 23. B; fact too. 17. Chromosomes uncoil last of all; that's D. 14. D; fact. 7. B; fact. 5. Use image size = actual size x magnification. 4. D... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
You labelled a bond, not the Carbon atom. The Carbon atom you meant can't be chiral because is had a double bond with O. Trichloromethane has only van der Waals and perhaps very weak permanent dipole forces, but the strongest intermolecular force is the hydrogen bonding. -
P1 MCQ's preparation thread for chemistry ONLY!!!!
2. 1 mole of H2 removes one C=C bond. At the beginning, there are 9 C=C bonds in the molecule; at the end, there are 4 (2 in one side chain, 1 in each of the other 2 side chains). 9-4=5. 16. Cl2 has to react with hot, concentrated NaOH to give ClO3- ions. The ox. no. of Cl in ClO3- is +5. 18... -
P1 MCQ's preparation thread for chemistry ONLY!!!!
The apparatus shown is used for reflux. Reaction 1 is nucelophilic substition and reaction 2 is oxidation of an alcohol; both these need reflux. The 3rd is the bromine water tes; it occurs at room temperature.