Biology; Chemistry; Physics: Post your doubts here!

[Abdullah Zahid]

and what was the isomer of butene b rite?

 

[Awesome12]

They had non electrolyte,like sugar or ethanol i think....they dont allow electricity to flow...

It was solid NaCl ,as in one paper there was a similar question, about in which circuit will the bulb be least bright.
I chose mercury, but it was wrong and the answer was one where there was NaCl (solid)

 

[Fate0]

The one that contained H2so4...it was easy.

No bro. Cu and Ag are besides each other. The voltage produced is VERY less.
It was (A). 100% Confirmed

 

[DaniyalK]

It was solid NaCl ,as in one paper there was a similar question, about in which circuit will the bulb be least bright.
I chose mercury, but it was wrong and the answer was one where there was NaCl (solid)

idk... in past paper 2s it always asked why solid NaCl doesn't conduct.

 

[Dark Destination]

No bro. Cu and Ag are besides each other. The voltage produced is VERY less.
It was (A). 100% Confirmed

Haha, A was Copper and Copper.

 

[Dark Destination]

So how many marks are you people expecting in paper 1 and paper 2?

 

[DaniyalK]

No bro. Cu and Ag are besides each other. The voltage produced is VERY less.
It was (A). 100% Confirmed

That one is used in purification of copper and it doesn't generate electricity ( You have to provide electricity).

 

[Fate0]

A had both Cu,no flow.

How would solid NaCl even allow it to flow.

Yes they do flow.

Anode --> Cu --> Cu2+ + 2e
On cathode --> Cu 2+ 2e --> Cu

I've seen the diagram in books and it had a bulb which lighted

 

[asadalam]

So how many marks are you people expecting in paper 1 and paper 2?

P1, 37-38,P2 72-74(at least now,discussion karke pata nai aur kitne kat deto ho tum log )
But overall i expect an A*

 

[Dark Destination]

Yes they do flow.

Anode --> Cu --> Cu2+ + 2e
On cathode --> Cu 2+ 2e --> Cu

I've seen the diagram in books and it had a bulb which lighted

Which book? That's not possible
If electricity is flowing when their is NO difference in re-activity, it would definitely flow when their is Ag and Cu, which have different re-activities.

 

[Fate0]

What you guys dont understand is that it cant be D because Ag and Cu are right beside each other. The voltage produced is very minimal. Like Mg and Ag say ja kar koi 2 V produce hoti hai.

 

[Dark Destination]

P1, 37-38,P2 72-74(at least now,discussion karke pata nai aur kitne kat deto ho tum log )
But overall i expect an A*

Those are good marks.
Which mcqs you getting wrong?

 

[Awesome12]

Yes they do flow.

Anode --> Cu --> Cu2+ + 2e
On cathode --> Cu 2+ 2e --> Cu

I've seen the diagram in books and it had a bulb which lighted

The anode will dissolve over time, so how will the circuit be completed

 

[asadalam]

Those are good marks.
Which mcqs you getting wrong?

Assumptions,dont know but surely i cant get full,and im not even sure about losing any in P2.

 

[Dark Destination]

But it would LIGHT.It did not state brightly,and the less there is difference the longer the bulb lights but the dimmer it is.Look it up.It would be dim but would be ALIGHT

And in A it won't light up at all right?

 

[Fate0]

Search google for copper electrolysis,they all have a DC supply,in books they give you a simpler one for understanding

Hm chalo.
Mera sirf aik yehi kat raha hai abhi tak :3
Paper 2 main InshALLAH 70+ Paper 1 main 38/37.

 

[asadalam]

I dont get why you cant understand,it was such a simple MCQ no need to create a fuss!

 

[asadalam]

And in A it won't light up at all right?

Of course not.

 

[Dark Destination]

Assumptions,dont know but surely i cant get full,and im not even sure about losing any in P2.

What did you do for which doesn't produce carbon?

 

[DaniyalK]

The mcq about burning 1g of carbohydrates, it was the first one, right?