Biology; Chemistry; Physics: Post your doubts here!

[faira]

draw the structure and u'll know that all hydrogen electrons are bonding bcz hydrogen has only one electron each and if its invlved it need to be bonded by that electron. and each carbon is bonded with four single bonds (1 with the other carbon and 3 with hydrogen atoms) got it >??

Okay thanx well sorry for being rude firstly n see my problem is that in a carbon atom there are 6 electrons n when 4 are bonded 2 of each carbon atom are left unused n arenot bonded so how can no of electrons not bonded be zero? plz explain again.

 

[faira]

Carbon's valency is satisfied ( it's four electrons are used in bonding)
Hydrogen's valency is satisfied (it's one electron is used in bonding )

No electrons are left behind!

yeah that's right bt isnt no f electron in carbon 6?

 

[multixamza01]

yeah that's right bt isnt no f electron in carbon 6?

Only outer most electrons take part in bonding! we ignore the 2 in the inner shell! 6-2 = 4!

 

[faira]

Only outer most electrons take part in bonding! we ignore the 2 in the inner shell! 6-2 = 4!

okay so whenever there is this kinda q v ll c the valence electrons only? well thankyou now i get it thanx again

 

[a.abid]

okay so whenever there is this kinda q v ll c the valence electrons only? well thankyou now i get it thanx again

haan na valence electrons laitay hain

 

[SalmanPakRocks]

 

[multixamza01]

View attachment 11051

sorry bro , i can't find my Periodic Table!

just calculate the moles of iodine by ( moles = mass/Ar ) and then the concentration by ( c = moles / volume )

remember to convert volume from cm3 to dm3 before calculation

See if that gets the answer!

 

[Translucent231]

0.04 C

 

[a.abid]

View attachment 11051

the answer is C because no. of moles=2.54/254=0.001
Now No. of moles x 1000/vol.=conc.
So= 0.001x1000/250=0.04

 

[ashiqbal]

i guess coz both the products formed are soluble
e.g
KNO3(aq)+HCl(aq)--->KCl(aq)+HNO3(aq)
KNo3(aq)+AgCl(s)--->KCl(aq)+AgNO3(aq)
its not suitable as we cant seperate them....
(correct me if m wrong)

have you ever heard about an acid reacting with salt???? KNO3 is salt!!!!

 

[ashiqbal]

need help with Q10(b)(iii):

 

[A star]

y does it seems like i have done every question i can and in exam i am like. where did this come from?

 

[A star]

need help with Q10(c):
View attachment 11056

add a reactive metal

 

[ashiqbal]

y does it seems like i have done every question i can and in exam i am like. where did this come from?

answer my question above! ^

 

[A star]

take magnesium or zinc ( u could loose marks if u choose sodium or potassium

 

[ashiqbal]

add a reactive metal

sorry i meant b(iii)

 

[A star]

answer my question above! ^

i think i already did

 

[ashiqbal]

i think i already did

yar b(iii)! c ghalti sai post ho gay tha!!

 

[malay]

Which gas contains the same number of molecules as 9 g of water?
A 2 g of hydrogen
B 14 g of nitrogen
C 32 g of oxygen
D 44 g of carbon dioxide

 

[A star]

no change