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Hi,
I do not understand why there will be 42 hydrogen atoms in the first place. The rest of it makes a lot of sense. Thank you.
for a saturated molecule: CnH2n+2
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Hi,
I do not understand why there will be 42 hydrogen atoms in the first place. The rest of it makes a lot of sense. Thank you.
hmmm, it was actually answered a page ago.Q6 guys
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
Number 8 ?? Answer D . If u can do this and explain it ur a genius! Hardest question! Please anyone explain it
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_1.pdf
question 2 ans. A
I am getting the answer but my school teacher says my method is wrong. I found the empirical formula using percentage composition by mass. what's the other way?
Thanks. Also, i want to know whether my method is wrong coz I am getting the right answer too.s08qp1
Just use proportion if its easier to visualise.
mass of N in 100 g of fertiliser = 15 g
mass of N in 14 g of fertiliser = (15/100) x 14= 2.1 g
moles of N in 14 g of fertiliser = 2.1 /14 = 0.15 mol
conc of N in 5 dm^3 of solution = 0.15/5 = 0.03 mol/dm^3
Are you able to post your working?Thanks. Also, i want to know whether my method is wrong coz I am getting the right answer too.
14: Ionisation energy decreases down the group.http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w07_qp_1.pdf
Q9 answer is B
Q14 answer A what about C??
Q19 answer is B i don't get how III is included?
Q26 shouldn't the answer be A like i was so sure isn't X a nitrile and we do hydrolysis with dilute to get carboxylic acid? answer is C
Q28 i know its an easy one but when we add H2 in the presence of Ni catalyst we dont change an aldehdy to alcohol do we? answer is A
Q32 how do we deduce 2 using that info?? answer is A
Q33 how 3??? answer is C
Q37 i have no idea answer B
Please help
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w07_qp_1.pdf
Q9 answer is B
Q14 answer A what about C??
Q19 answer is B i don't get how III is included?
Q26 shouldn't the answer be A like i was so sure isn't X a nitrile and we do hydrolysis with dilute to get carboxylic acid? answer is C
Q28 i know its an easy one but when we add H2 in the presence of Ni catalyst we dont change an aldehdy to alcohol do we? answer is A
Q32 how do we deduce 2 using that info?? answer is A
Q33 how 3??? answer is C
Q37 i have no idea answer B
Please help
26 as well please!!!http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_1.pdf
Help needed in question 6,15,
22 how do YOU KNOW??!!
27
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s08_qp_1.pdf
Help needed in question 6,15,
22 how do YOU KNOW??!!
27
Thanksw07qp1
Qn 9 :
moles of SO3 2- : moles of electrons : moles of metal
0.0025 : ? : 0. 005
1 :? : 2
1 : 2 : 2
Q14. IE should be decreasing down the Group.
2 mol of metal gained 2 mol of electrons
1 mol of metal gained 1 mol of electron (oxidation state will thus decrease by 1)
Original oxidation state of metal = +3
Final oxidation state = +3 - 1 = +2
Q26. We use HCN (with trace NaCN) to step up carbonyls. We use NaCN or KCN to step up halogen alkanes.
Q19. Put the iodine atoms on 1st and 2nd carbon. CH2ICHICH3, chiral carbon is the middle carbon.
Q28. Ketones and aldehydes can be reduced by H2 to alcohols. Only COOH wouldn't be reduced by H2.
Q32. Burns readily means CO --> CO2 exothermic.
1. CO2 more stable than CO in terms of energy
2. as explained, exothermic reaction
3. ratio of CO2 is high compared to CO, therefore Kc is high
Q33.
Statement 1: (False) The gas is exerting the same pressure as the atmosphere outside, otherwise the plunger will either move left or right.
Statement 2: (True) When plunger moves inwards, it causes the pressure to increase, the eqm will shift to the left to reduce pressure (produce less moles of gas).
Statement 3: (True) For every one mole of PCl5 dissociated, two moles of gases were formed (1 mol of PCl3 and 1 mol of Cl2). So total volume of gases after dissociation is more than original volume of gas without dissociation.
Q37
1. (Correct) CaO + ND4Cl --> CaCl2 + D2O + ND3
2. (Correct) CH3CN + NaOD + D2O --> CaCOONa + ND3
3. (wrong) NaOD + NDH3Cl --> NaCl + D2O + NH3 or NaCl + DHO + NDH2
Thanks14: Ionisation energy decreases down the group.
19: The molecule is CH3-CHI-CH2I
26: Halogenalkane react with NaCN not HCN
28: H2 in presence of Ni catalyst also reduces aldehyde to alcohol.
32: As CO burns readily to form CO2 so CO2 is more stable in which carbon is+4.
Formation of CO2 is formation of CO and also combustion of CO so combustion of CO is negative so formation of CO2 is more negative.
As more CO2 is more produced so equilibrium constant is high.
33: More moles of gas are produced so one mole occupies 24dm^3 so more volume.
37: Replace D with H and then look at the reactions.
Thanks
i am still confused about
Q9 how did you find the moles? shouldn't metallic salt be 0.10/(50*10^-3)=2??
SO3 2- be 0.10/(25*10^-3)=4??
Thanks
Q19 why not
CH3-CH2-CHI2??
View attachment 44961 explain me ques 5 and 6
my bad Thanks againMoles = conc x volume
you did it as moles = conc/volume ?
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