[nemzy]

Lets say you pipet into a 250 mL volumetric flask the following:

10 ml of 3e-4 M bromscresol green solution
25 mL of 1.6 M acetic acid (HC2H3O2)
10 mL of .200 M KC1 Solution

and diluted to the 250 mL mark

What is the molarity of acetic acid in this solution?

Do you calculate the number of moles in the 25 mL solution since you know the molarity, then when u get the moles you find molarity over 250 mL?

2nd problem.. Lets say you have a solution with the following:

10 mL of 3e-4 Bromscresol green solution
10 mL of .160 M sodium acetate solution
and diluted to 250 mL mark

What is the mles acetate present?

Do you calculate the # of moles over just 10 mL?

Does the # of moles stay constant even though you add more volume?  I think i heard that somewhere but not sure

[Mitch]

for part A) M1V1=M2V2 just solve for M2

[AWK]

Do you calculate the # of moles over just 10 mL?

Does the # of moles stay constant even though you add more volume?  I think i heard that somewhere but not sure

YES - law of conservation of matter should always work in chemistry.