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

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: winnie101 on May 15, 2010, 02:35:01 pm

Title: bio practical as
Post by: winnie101 on May 15, 2010, 02:35:01 pm

could someone plz explain to me how to make the solutions for june 2009 practical 32. and ques 2b how do i calculate the area of the field of view. i dont get anything from the marking scheme.
plz and thank u
any tips on wat to study is welcome

Title: Re: bio practical as
Post by: Sue T on May 17, 2010, 01:35:11 pm

u can take 0cm3 water, 10 cm3 salt , <the percentage conc is identical cuz its = (10/100) * (salt/water)>
th last column is simplt dividin by 2
 
then take 7.5water & 2.5 salt
then 2.5 water n 7.5 salt
then 2.5 water n 7.5 salt

there u go the readings are equally spaced + 3 readings are enough (i guess)

i wrote this in a hurry so if am not clear pls let me no

Title: Re: bio practical as
Post by: 247sports on May 17, 2010, 01:42:58 pm

could someone plz explain me the process for serial dilution ???

Title: Re: bio practical as
Post by: AS-Girl on May 17, 2010, 01:49:22 pm

Check this out
might help in getting the idea
http://www.youtube.com/watch?v=99ec1eDVkaE&feature=related