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ChemistryFooL
#1
Feb17-12, 08:40 PM
P: 5
Hi guys ! I'm in serious need of help!

Could you guys teach me how to attempt the following questions? I've tried everything..from reading up the notes(which has been trimmed along the years to make people pass)..to asking my teacher(He only explains briefly and in a way which i cant understand).
My exams are coming soon and it'll be mostly about acid and base reaction(pH & dissociation(those low level questions)).

I'm really at wits end and i am in seriously need of help !

Questions

1. Calculate the final pH of a solution if 500mL of 10M H2SO4 is mixed with 2L of 3M HCL & 30L of de-ion water.
( I used the titration method to find the molarity of de-ionized water( M1V1=M2V2) After that, i broke up HCL into H3O+CL- and i got lost)

2. Calculate the number of H atoms in 0.35moles of C6H12O6.
(i do not know how to start ..how do i apply the avogadro's rule into this type of questions?(6.02X10^23)

3. How do u know when will be the equivalence point of a buffer?
( i know that strong base and strong acid buffer will give u a equivalence of 7...what about weak acid and strong base?)

4. How do u calculate the pH if base in excess is added to an acid buffer solution?
( My teacher taught us only the ICE table,Buffer equation(pH=kpa+log(salt/acid)), and Ka or Kb.. is there any way which i can use along what my teacher has taught me, to tackle this type of excess buffer question?)

Thanks ! =(
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