Biology; Chemistry; Physics: Post your doubts here!

[princess Anu]

Please help me in this part.
please show the working as well.

A
because Mn02 is the catalyst and catalyst increases the rate of reaction only.

 

[kirann]

1: B
2: A
3: C
are these answers correct?

no, answers are A C D

 

[FLRNAB]

Well, i believe Hard-work is not the key to success.
Praying with heart is. :')

That's your belief. Mine is Himat-e-Mardaan Madaad-e-Khuda. Praying with heart will make your kismat better.

I feel like i've forgotten chemistry

http://3.bp.blogspot.com/-AxsSNeYWa...Q1Av5OAUtLg/s1600/I+have+to+pass+the+exam.gif

 

[Maganius]

View attachment 41610 View attachment 41611 View attachment 41612
im stuck plz help

A , C and D

 

[kirann]

I feel like i've forgotten chemistry

you will keep feeling like this till the last minute of the start of exam it happens to me alot

 

[Muhammad_Hamza]

this questiion is about the catalyst and i think it should be (a)
cuz no volume is increses using a catalyst, catalyst is not used up chemically in the reaction, so it will not react and no mass will decrease.

Thanks! its the correct answer and i got working also

 

[kirann]

A , C and D

now explain

 

[Maganius]

Please help me in this part.
please show the working as well.

A

 

[princess Anu]

A , C and D

how can the answer be D to last one ?

 

[kirann]

confused!! somebody explain and tell me the reason as well

 

[kirann]

how can the answer be D to last one ?

i could not understand the other two even

 

[princess Anu]

View attachment 41615
confused!! somebody explain and tell me the reason as well

Because they cannot be oxidised any further.
Fe 2+ can be oxidised into fe 3+ but fe3+ cannot be further oxidised to fe 4+ etc

 

[Dark Destination]

That's your belief. Mine is Himat-e-Mardaan Madaad-e-Khuda. Praying with heart will make your kismat better.

A lot of people think that, the entire world thinks that.
But it's a different story for every person. Everyone has a different philosophy.

One can solve a million past papers, read a million books, but in the end what Allah wants will happen.
That just proves how we have no control of our lives. It's all up to Him.

All we can do is, Hope for the best. (Y)

But everyone has a different opinion. xD

 

[princess Anu]

i could not understand the other two even

in the second one see the moles of HCL are double in experiment 2 so the yield of product will be greater and when using zinc powder instead of zinc pieces the rate increases as well in exp 2 and thus the graph for exp 2 levels off quickly

 

[Maganius]

now explain

6. In experiment Q same volume of sulphuric aicd of concentration 0.100 mol/dm^3 is used. Sulphuric acid being diprotic, produces double the amount of H+ ions producing double the volume of hyrdogen gas. As the concentration of acid is doubled, the speed of reaction will be faster and the gradient will be steeper than in experiment P.



3. Zinc Sulphate is soluble in water and zinc power ( a metal ) is insoluble in water.


5. Propanol contains three carbon atoms which produce an acid of three carbons. When this acid reacts with propanol, propylpropanoate is produced

 

[kirann]

plz explain asap plz

 

[Maganius]

how can the answer be D to last one ?

Ops! it's C

 

[Dark Destination]

View attachment 41616
plz explain asap plz

B, C.

That's just basic concepts of Chemistry Haven't you read that in the book?

 

[princess Anu]

View attachment 41616
plz explain asap plz

d,c?

 

[kirann]

6. In experiment Q same volume of sulphuric aicd of concentration 0.100 mol/dm^3 is used. Sulphuric acid being diprotic, produces double the amount of H+ ions producing double the volume of hyrdogen gas. As the concentration of acid is doubled, the speed of reaction will be faster and the gradient will be steeper than in experiment P.



3. Zinc Sulphate is soluble in water and zinc power ( a metal ) is insoluble in water.


5. Propanol contains three carbon atoms which produce an acid of three carbons. When this acid reacts with propanol, propylpropanoate is produced

got it