Biology; Chemistry; Physics: Post your doubts here!

[funky brat]

Who knows?The examiner might be a crazy cat lady

Okay, do one thing you write the cute answers and get the distinction. I really don't mind.

 

[Faizan Muhammmad]

Who knows?The examiner might be a crazy cat lady

then she wont be quite pleased with locking a cat in a box

 

[Tuba noor]

it is X butanol , as total carbon atoms in an ester are seven. The acid is propanoic acid containing 3 carbons, therefore the alcohol must be containing four carbons, which is butanol

 

[funky brat]

then she wont be quite pleased with locking a cat in a box

He has a point.

 

[funky brat]

it is X butanol , as total carbon atoms in an ester are seven. The acid is propanoic acid containing 3 carbons, therefore the alcohol must be containing four carbons, which is butanol

Thanks a lot. I got that.

 

[FLRNAB]

Not after each answer but it is with those answers specially graphs etc, where they accept +/- 1. I think.

What does these mean? ^

 

[Faizan Muhammmad]

What does these mean? ^

1 mark for that

 

[funky brat]

What is the best way to wash the apparatus for titration? There was a n MCQ and the answer was first with tap water then with distilled water. Dark Destination, remember?
But question 8 part e says with solution H.
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_w08_qp_4.pdf

 

[Awesome12]

What is the best way to wash the apparatus for titration? There was a n MCQ and the answer was first with tap water then with distilled water. Dark Destination, remember?
But question 8 part e says with solution H.
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_w08_qp_4.pdf

During titration, to rinse the FLASK,
First rinse with tap water
Then rinse with distilled water


During titration, to rinse BURETTE
First rinse with water
Then with acid

 

[FLRNAB]

What is the best way to wash the apparatus for titration? There was a n MCQ and the answer was first with tap water then with distilled water. Dark Destination, remember?
But question 8 part e says with solution H.
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Chemistry (5070)/5070_w08_qp_4.pdf

Water will dilute the acid so H is used to remove any water.

 

[Shafin Ahmed]

Assalamu Walaikum,
I have a doubt on Biology MCQ as follows:
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s10_qp_11.pdf

For Question no 35 , the answer is D and the explanation in Examiners Report is
"Sperm deposited on day 10 will still be viable on day 13. Eggs ovulated on day 15 are still viable on
day 17, so the fertile period extends for 7 days."

I don't quite get it. After being viable on day 13 , sperms will die so how will they fuse with eggs ovulated on day 15. Moreover, even if not fused then the E.R means that it can even be fused in day 17 ! How is that possible?

Anyone please explain it to me?

 

[princess Anu]

funky brat

Answer for root one is B?

 

[FLRNAB]

Does anyone else use french curves for drawing graphs?

 

[Shafin Ahmed]

Does anyone else use french curves for drawing graphs?

Yes, I do

 

[Awesome12]

Assalamu Walaikum,
I have a doubt on Biology MCQ as follows:
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s10_qp_11.pdf

For Question no 35 , the answer is D and the explanation in Examiners Report is
"Sperm deposited on day 10 will still be viable on day 13. Eggs ovulated on day 15 are still viable on
day 17, so the fertile period extends for 7 days."

I don't quite get it. After being viable on day 13 , sperms will die so how will they fuse with eggs ovulated on day 15. Moreover, even if not fused then the E.R means that it can even be fused in day 17 ! How is that possible?

Anyone please explain it to me?

See lets say the sperms are released on day 10
They will survive till day 13
The eggs are released on day 15. They will ovulate, and survive for 2 days, until day 17.
Now there is no sperms or eggs, thus the fertile period ends

 

[ZohaKhan]

funky brat explain me these three man

 

[asadalam]

funky brat explain me these three man

6. A . Esters have carboxylic acid first and then alcohol so you can see their names by the number of carbon atoms
7. A . We're making a polyAMIDE and theres only one option thats nylon
9.B . Its endo so temp of surroundings will decrease,but slowly return to normal as always.

 

[Awesome12]

6. A . Esters have carboxylic acid first and then alcohol so you can see their names by the number of carbon atoms
7. A . We're making a polyAMIDE and theres only one option thats nylon
9.B . Its endo so temp of surroundings will decrease,but slowly return to normal as always.

Won't 9 be A, as it is being constantly stirred until no further change in temp is there? If we stirred it and then left it, then it would have been B

 

[Shafin Ahmed]

See lets say the sperms are released on day 10
They will survive till day 13
The eggs are released on day 15. They will ovulate, and survive for 2 days, until day 17.
Now there is no sperms or eggs, thus the fertile period ends

If sperms survive till day 13 then how will they fuse with the egg released at day 15 ?
Thanks

 

[Awesome12]

If sperms survive till day 13 then how will they fuse with the egg released at day 15 ?
Thanks

Fusing is fertilization and not ovulation