Physics, Chemistry and Biology: Post your doubts here!

[My Name]

Please what are cladistics...please give examples

Mind I ask is do they mention this in the syllabus? :3

 

[Ahmed Elsiddig]

Mind I ask is do they mention this in the syllabus? :3

It is mentioned

 

[My Name]

It is mentioned

Sorry cant help you.
Syllabus 2016-2018 ?

 

[Ahmed Elsiddig]

Sorry cant help you.
Syllabus 2016-2018 ?

2015

 

[Muaaz Iqbal]

Well most of these questions have similar answers :
(f) For the first 2.. u just have to read the value from the graph.. i suppose thats pretty simple
(g) For the chemical reaction: If temperature increases.. it'll always be exothermic.. and if temperature decreases then endothermic..other than that if a precipitate is formed they'll mention it in the question.. so its a precipitation reaction....and if its just acid base given and no reference to temperature.. than u can write neutralisation reaction
(h) always remember that volume is inversely proportional to concentration... so write now they have doubled the volume so the concentration will be halved... consequently the temperature change will be less/ halved.
(i) the answer to this will always be the initial temperature u recorded... the first reading from the table ...ALWAYS
these type of questions will have similar answers to the above.. except the numbers will be changed

Thank's Bruh...

 

[topper_sb7]

can anyone help me out with salt analysis in chemistry (paper 6)
any resources or guidance would be helpful. THANKS.

 

[Saad the Paki]

can anyone help me out with salt analysis in chemistry (paper 6)
any resources or guidance would be helpful. THANKS.

U mean as in to identify the type of salt present?

 

[topper_sb7]

U mean as in to identify the type of salt present?

Yes.

 

[Saad the Paki]

Yes.

This should help

 

[Saad the Paki]

Just learn these rules

 

[My Name]

This should help

can anyone help me out with salt analysis in chemistry (paper 6)
any resources or guidance would be helpful. THANKS.

This will help as well

 

[Saad the Paki]

Why hasn't the timer for M/J session 2015 started yet..!?

 

[NOneed2speedd]

salam every1
well i need help with this question of p6
first, is the second graph correct consedering part (e)
and second question is that in part (d) I wrote that all the acid was used up but answer was all zinc used up as acid was in excess so i want to know that how would we knw weather zinc is in excess or acid

 

[Saad the Paki]

salam every1
well i need help with this question of p6
first, is the second graph correct consedering part (e)
and second question is that in part (d) I wrote that all the acid was used up but answer was all zinc used up as acid was in excess so i want to know that how would we knw weather zinc is in excess or acid

Lol.. How will the acid get used up... since they are constantly adding more and more HCL until no more reaction happens and the SAME mass of zinc was being used so obviously the acid will be in excess and zinc will be reacted (used up) completely
No the graph u've drawn is incorrect...zinc granules have bigger surface area than powder...so i hope u know that if surface area increases reaction rate decreases thus the the graph will be less steep hence BELOW the original graph... since the same mass of zinc (which means same number of moles) is being used same volume of gas produced...

 

[NOneed2speedd]

Lol.. How will the acid get used up... since they are constantly adding more and more HCL until no more reaction happens and the SAME mass of zinc was being used so obviously the acid will be in excess and zinc will be reacted (used up) completely
No the graph u've drawn is incorrect...zinc granules have bigger surface area than powder...so i hope u know that if surface area increases reaction rate decreases thus the the graph will be less steep hence BELOW the original graph... since the same mass of zinc (which means same number of moles) is being used same volume of gas produced...

Thank u very much for ur help...

 

[NOneed2speedd]

Lol.. How will the acid get used up... since they are constantly adding more and more HCL until no more reaction happens and the SAME mass of zinc was being used so obviously the acid will be in excess and zinc will be reacted (used up) completely
No the graph u've drawn is incorrect...zinc granules have bigger surface area than powder...so i hope u know that if surface area increases reaction rate decreases thus the the graph will be less steep hence BELOW the original graph... since the same mass of zinc (which means same number of moles) is being used same volume of gas produced...

Btw as far as i knw when S.A increases, the rate of reaction increases? No?

 

[masterex567]

Btw as far as i knw when S.A increases, the rate of reaction increases? No?

Yes, that's true.
But granules have smaller surface area, since they have exposure to less reacting particles.
When you make it powder, then surface area increases with more exposure.

 

[NOneed2speedd]

Yes, that's true.
But granules have smaller surface area, since they have exposure to less reacting particles.
When you make it powder, then surface area increases with more exposure.

thanks. ....

 

[Abdulrhman999]

plz if anyone have idea about the phy 0625 (2015) exam plz send it to me my exam after few weeks. THANKS
[email protected]

 

[NOneed2speedd]

plz if anyone have idea about the phy 0625 (2015) exam plz send it to me my exam after few weeks. THANKS
[email protected]

When is ur exam? And which variant?