Question

Five standard solutions of HBr are prepared by serial dilution in which, at each stage, 10.00mL are diluted to 150.00mL. Given that the concentration of the most dilute solution is 2.37x10^-6M, determine the concentration of the original HBr stock solution.

Answer 1

@Shalante

Answer 2

@CShrix

Answer 3

Sorry man, I don't remember how to do this :( Been a few years

Answer 4

It's fine. Thanks anyway

Answer 5

@UnkleRhaukus

Answer 6

@kaylee_crps_strong

Answer 7

@mkerr017

Answer 8

@abb0t

Answer 9

@jebonna

Answer 10

@jebonna

Answer 11

@abb0t

Answer 12

@imqwerty

Answer 13

you use the c1v1=c2v2 equation so
c1= original concentration
c2= new concentraion
v1= original volume
v2= new volume
so from that question you know that the original volume was 10.0mL and the new volume is 150.0mL and for this equation to work you have to convert these values into litres :) so thats mL/1000 to give litres
hence 10mL/1000= 0.01L
150mL/1000= 0.15L
also from the question it tells you that the new concentration value (c2) is 2.37x10^-6
so if you substitute all the values you know into the equation c1v1=c2v2 you get
c1 x 0.01= 2.37x10^-6 x 0.15
then you have to rearrange this to be able to work out c1 so that would be
c1=(2.37x10^-6 x 0.15)/ 0.01= 3.555x10^-5
i hope it helped :)

Answer 14

So you get 3.55x10^-5? You don't need to do it 4 times?

Answer 15

the units for that would be M and nope because the question is only asking you to find the concentration of the original stock

Answer 16

So if I'm not given a place for exponents should I put .00003555?

Answer 17

yep that should be fine xD

Answer 18

thanks

Answer 19

@Ramzy197

Answer 20

no problem :)