IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: sweetie on April 12, 2010, 05:12:03 pm

Title: NO 1 IS GETTIN IT !!!!!!!!!!
Post by: sweetie on April 12, 2010, 05:12:03 pm

I ASKED MY TUTOR , AS WELL AS MANY OTHER PPL, BUT THEY'RE ALL GETTING DA ANS. TO Q2 OF THIS PAPER as  0.05 , SO IF ANY1 HAS GOT AN  XPLAINATION 4 WHY IS 0.03 THE CORRECT ANSWER PLZ POST IT !!!!

Title: Re: NO 1 IS GETTIN IT !!!!!!!!!!
Post by: Amr Fouad on April 12, 2010, 05:24:14 pm

you should ask nid..

shes the best in shemistry

Title: Re: NO 1 IS GETTIN IT !!!!!!!!!!
Post by: Amr Fouad on April 12, 2010, 05:24:39 pm

chemistry* lol

Title: Re: NO 1 IS GETTIN IT !!!!!!!!!!
Post by: sweetie on April 12, 2010, 05:28:53 pm

ya, i kno
nid plzzz help!!!!!!!!!!!!!

Title: Re: NO 1 IS GETTIN IT !!!!!!!!!!
Post by: Phosu on April 12, 2010, 05:42:34 pm

ok
so there is 15g of N in 100g of fertilizer, so 14g of fertilizer will contain how many g of N
 N           fertilizer
15            100
x                14     x= 2.1g

n=cv, we have the volume but to find the conc we need moles
so number of moles in 2.1g of nitrogen, n=2.1/14 = 0.15 moles

now u can use the formula
c=n/v  c=0.15/5 = 0.03 mol/dm³