Biology; Chemistry; Physics: Post your doubts here!

[ashiqbal]

both are dangerous at high voltage but i think at high voltage AC is safer...

nope!

 

[scouserlfc]

both are dangerous at high voltage but i think at high voltage AC is safer...

Dude how come Ac is safer both carry the same hazards,they have the same pd. same current so how are they different,i think if u compare Ac with Dc u might find AC very dangerous as it may have the ability to keep u attracted or repel u away due to the different polarities each time and the charge of ur body

 

[multixamza01]

Dude how come Ac is safer both carry the same hazards,they have the same pd. same current so how are they different,i think if u compare Ac with Dc u might find AC very dangerous as it may have the ability to keep u attracted or repel u away due to the different polarities each time and the charge of ur body

exact - ta -ly

 

[Spidey21]

well...there has to be safer..atleast one of them..:/

 

[amna shah]

WHAT ARE THE PRODUCTS OF REACTION BETWEEN ACID AND SULFATE/CHLORIDE SALTS .. WE ALL KNOW OXIDES PRODUCE H2O AND CARBONATES CO2 AND H2O BUT THERE IS NO MENTION OF SULFATES/CHLORIDE ALSO IN THE DECOMPOSITION THERE IS NO DECOMPOSITION TABLE FOR SULFATES CHLORIDES ETC AND THEY ARE COMMON IN EXAMS .... ANYONE HAS ANY IDEA ABOUT THIS ?

 

[Dukeofwin]

write --> Image (drawn) length/actual length = 12/6 = x2
dont forget to write the times symbol (x) before magnification.
if the actual image is already magnified, eg. x500, then you will have to do like this -->(12/6) * 500 = x1000

Thanks a ton

 

[DANGERBP]

hey do u have notes for edexcel chem unit 3 ! ?
thankss =p

 

[multixamza01]

WHAT ARE THE PRODUCTS OF REACTION BETWEEN ACID AND SULFATE/CHLORIDE SALTS .. WE ALL KNOW OXIDES PRODUCE H2O AND CARBONATES CO2 AND H2O BUT THERE IS NO MENTION OF SULFATES/CHLORIDE ALSO IN THE DECOMPOSITION THERE IS NO DECOMPOSITION TABLE FOR SULFATES CHLORIDES ETC AND THEY ARE COMMON IN EXAMS .... ANYONE HAS ANY IDEA ABOUT THIS ?

I don't have an idea, let me try though !

2HCl + BaSO4 -----> BaCl2 + H2SO4

=> Imma Genious! These are double displacement reactions . just swipe the places of different ions and you'll reach an answer .

for Chlorides :

HNO3 + NaCl -----> NaN03 + HCl

=> As far as i can deduce , the reaction of Acid + Sulfate/Chlorides produce Acid + Salt

 

[convent2012]

i want some help in
5090/12/O/N/11
13 , 16 , 29 , 32
5090/11/O/N/10
23, 25, 28

w09 PAPER 1 qp1 q16, q14, q9​

s09 PAPER1 qp1 q5, q17, q19​

 

[multixamza01]

i want some help in
5090/12/O/N/11
13 , 16 , 29 , 32
5090/11/O/N/10
23, 25, 28

O/N 2011
13 . A . Amylase is denatured at very high (90 degree) and inactive at very low (10 degree) temp!

16 . The questions statement is set to confuse the candidates . The sequence is not 1 ----> 2 , it's 2 ---> 1 ! Answer is A! As Superior Vena Cava is a Vein with valves!

29 . A , is again the answer . The clue is that many insects can live on one cow , so the number of insects would be very greater than that of cows . This is shown by pyramid three , which is the pyramid of numbers . Since it's the only option that shows this , we choose A as our answer .

32 . Organisms at S feed on leaves . So the would feed on both P and Q ! And The butterflies will feed on insects! So C is the answer .


----
O/N 2010

23 . B. Pupil dilate when light intensity decreases . Muscle part is too be learnt from book.

25 . D , knowledge from book!

28 . Question refers to the removal of nitrates . C and D are for supply of nitrates . and A is just a feature of plants . B is the only sensible answer.

Hope this was helpful

 

[beeloooo]

I don't have an idea, let me try though !

2HCl + BaSO4 -----> BaCl2 + H2SO4

=> Imma Genious! These are double displacement reactions . just swipe the places of different ions and you'll reach an answer .

for Chlorides :

HNO3 + NaCl -----> NaN03 + HCl

=> As far as i can deduce , the reaction of Acid + Sulfate/Chlorides produce Acid + Salt

DIS IS RYTTT !!! MULTIXAMZA01

 

[multixamza01]

DIS IS RYTTT !!! MULTIXAMZA01

 

[convent2012]

O/N 2011
13 . A . Amylase is denatured at very high (90 degree) and inactive at very low (10 degree) temp!

16 . The questions statement is set to confuse the candidates . The sequence is not 1 ----> 2 , it's 2 ---> 1 ! Answer is A! As Superior Vena Cava is a Vein with valves!

29 . A , is again the answer . The clue is that many insects can live on one cow , so the number of insects would be very greater than that of cows . This is shown by pyramid three , which is the pyramid of numbers . Since it's the only option that shows this , we choose A as our answer .

32 . Organisms at S feed on leaves . So the would feed on both P and Q ! And The butterflies will feed on insects! So C is the answer .


----
O/N 2010

23 . B. Pupil dilate when light intensity decreases . Muscle part is too be learnt from book.

25 . D , knowledge from book!

28 . Question refers to the removal of nitrates . C and D are for supply of nitrates . and A is just a feature of plants . B is the only sensible answer.

Hope this was helpful

thanku so much

 

[ailg1996]

Plz solve this question

 

[smzimran]

Plz solve this question

AoA,
Use P = F * A
P is atmospheric pressure (1 atm) in Pascals
F is the force which you need to find
A is the baser area, which is given.

 

[ashiqbal]

WHAT ARE THE PRODUCTS OF REACTION BETWEEN ACID AND SULFATE/CHLORIDE SALTS .. WE ALL KNOW OXIDES PRODUCE H2O AND CARBONATES CO2 AND H2O BUT THERE IS NO MENTION OF SULFATES/CHLORIDE ALSO IN THE DECOMPOSITION THERE IS NO DECOMPOSITION TABLE FOR SULFATES CHLORIDES ETC AND THEY ARE COMMON IN EXAMS .... ANYONE HAS ANY IDEA ABOUT THIS ?

can u please post a question which asks you to write about reaction of acid with salts such as sulfates or chloride or nitrates? acids only react with carbonates as CO3 salts are basic. and as far as i know, only decomposition of oxides or OH come, but please correct me, and post any question that proves otherwise.

 

[multixamza01]

can u please post a question which asks you to write about reaction of acid with salts such as sulfates or chloride or nitrates? acids only react with carbonates as CO3 salts are basic. and as far as i know, only decomposition of oxides or OH come, but please correct me, and post any question that proves otherwise.

Read below!

I don't have an idea, let me try though !

2HCl + BaSO4 -----> BaCl2 + H2SO4

=> Imma Genious! These are double displacement reactions . just swipe the places of different ions and you'll reach an answer .

for Chlorides :

HNO3 + NaCl -----> NaN03 + HCl

=> As far as i can deduce , the reaction of Acid + Sulfate/Chlorides produce Acid + Salt

 

[ashiqbal]

Read below!

past paper question please?

 

[multixamza01]

past paper question please?

don't know! she asked for explanation . i explained ! ab mitti pao !

 

[ashiqbal]

don't know! she asked for explanation . i explained ! ab mitti pao !

LOL!! actually yar i qouted her post kai why is she asking that question? i am not arguing about your post! !