Biology; Chemistry; Physics: Post your doubts here!

[Bhaijan]

5090_w04_qp6 (Alternate to practical)
i dont understand what units be used to express the measurements, i read the mark scheme but i dont understand



5090_w04_ms6

 

[Haris Zulfiqar]

magnification= length of drawing
length of actual photo

Show working
Suppose answer is 3 then it is written as x2 ( multiply by 2 )

 

[muaz_ali]

I need a full conceptual answer as required in olevel
Q) Why zinc nitrate does not react with HCl ?

In the previous posts some said that nitrate has a strong bonding and does not allow zn to be displaced but i need the answer why precipitation does not take place

Its because salts usually do not react with acids. That's a property and we need not to know more.

 

[Haris Zulfiqar]

Its because salts usually do not react with acids. That's a property and we need not to know more.

in precipitation any soluble salt can react with acid or any other solublle salt
So why it is not in this case

 

[muaz_ali]

in precipitation any soluble salt can react with acid or any other solublle salt
So why it is not in this case

I have read that mcq and others. It usually occured b/w Alkali & soluble salt and mostly two soluble salts. And I have read about that CaCO3 + HCl ---> H2CO3 + CaCl2 reaction as well. However it's not mentioned in our syllabus that which acid react with a specific salt to incur precipitation. Allah de saharay hun. :3

 

[Haris Zulfiqar]

I have read that mcq and others. It usually occured b/w Alkali & soluble salt and mostly two soluble salts. And I have read about that CaCO3 + HCl ---> H2CO3 + CaCl2 reaction as well. However it's not mentioned in our syllabus that which acid react with a specific salt to incur precipitation. Allah de saharay hun. :3

Thanks for your effort but i have found the solution
in precipitation two soluble substances react to form an insolube salt and a soluble salt but in this case the result is both soluble salts are formed
furthermore the ionic equation for this reaction is nothing as all ions are spectator
Thanks for your efforts

 

[muaz_ali]

Thanks for your effort but i have found the solution
in precipitation two soluble substances react to form an insolube salt and a soluble salt but in this case the result is both soluble salts are formed
furthermore the ionic equation for this reaction is nothing as all ions are spectator
Thanks for your efforts

It was a pleasure. Well, then ZnCL2 forms?

 

[muaz_ali]

I mean I have seen HDMI cables conducting electricity but what about this?

 

[Danyamehmud]

Assalam-o-Allaikum and Hi everyone ,
hope u all are doin great !

Well as the topic says help for chemistry biology and Physics is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books.

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz !

Assalam-o-Allaikum and Hi everyone ,
hope u all are doin great !

Well as the topic says help for chemistry biology and Physics is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books.

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz !

 

[Danyamehmud]

Hey

Assalam-o-Allaikum and Hi everyone ,
hope u all are doin great !

Well as the topic says help for chemistry biology and Physics is available here that means that u can ask any mind blowing question or ask any question regarding a particular topic or ask abt any questions from Past paper or any of your text books.

I made this topic so that people dont make many posts asking abt bio,physics or chemistry individually but they can post their reply here where it can be answered with ease and the members wont have to go searching for topics to help! !

So what are u waiting for now write ur questions here !
THANKS and Bye or Allah Hafiz !

hey there can anyone help me out in phys atp's
It's very imp cause cie exams up.

 

[Alpha Destro]

I need a full conceptual answer as required in olevel
Q) Why zinc nitrate does not react with HCl ?

In the previous posts some said that nitrate has a strong bonding and does not allow zn to be displaced but i need the answer why precipitation does not take place

why doesnt it react shouldnt there be a displacement reaction as zinc is more reactive than hydrogen

 

[Sweet Guy]

A sample of hydrate ion (II) sulphate has formula Fe2So4.XH20..The Compositon of Water is 45.3%.Calculate value of X .

 

[Haris Zulfiqar]

why doesnt it react shouldnt there be a displacement reaction as zinc is more reactive than hydrogen

Thanks for your effort but i have found the solution
in precipitation two soluble substances react to form an insolube salt and a soluble salt but in this case the result is both soluble salts are formed
furthermore the ionic equation for this reaction is nothing as all ions are spectator
Thanks for your efforts

Hope it helps, pray for all

 

[tayyab9801]

what is polarity in magnatism? can someone please do 5054/42/M/J/12/question 4(a) part only.

 

[Sweet Guy]

what is polarity in magnatism? can someone please do 5054/42/M/J/12/question 4(a) part only.

#tayyab9801
Well the answer is South Pole
Now Explanations
First of all u need to understand what is Polarity ?
The state of having two opposite or poles, opinions, or aspects.
Properties of Magnets
Like Charges Repel & Unlike charges attract
So Old magnet Consist Of Two Poles North Pole and Sound Pole ,
The Compass north Pole is attracted toward the South Pole

Hope This Helped You

 

[nader osta]

pls im writing cie o levels in two days. i m a smart student but have a problem answering questions, and marking scheme doesnt help. i have the idea for the answer but dont know how to express it.

 

[Alpha Destro]

pls im writing cie o levels in two days. i m a smart student but have a problem answering questions, and marking scheme doesnt help. i have the idea for the answer but dont know how to express it.

Which subject ? englsh??

 

[nader osta]

Which subject ? englsh??

thanks for even answering. no in biology and physcics

 

[nader osta]

especially those essay questions

 

[Alpha Destro]

especially those essay questions

Bio aakh i hate long question as well so hard writing what you mean.Brother the thing is u need to be familiar with a few "terms" the examiner is looking for in your question ,the long and better way to learn them is through the book the other quicker and risky way is to read marking schemes again and again as they contain only the key words the examiners r looking for, u read them again and again they get stuck in your head ,so you dont have a problem writing you r anwers. Remember that the examier will not deduct marks because you used wierd sentences like "..the ball was moving up and down..." as long as your anwser makes sense they will give you the marks you deserve ,i have heard they are God fearing ppl.

Btw r u giving english aswell