calcs (1 Viewer)

[fullonoob]

<DIR>an environmental chemist tests a water sample and find it contains 210 ppm of nitrate ions. He takes 10mL of solution and adds 90mL of distilled water to it. What is the conc. of nitrate ions in this 100mL solution?
Justify your choice
</DIR>

 

[ibbi00]

Isn't it as simple as c1v1=c2v2 ?

EDIT: Is answer 21 ppm?

 

[fullonoob]

i think so
210 mg/ 1000 mL : c2 / 100mL
c2 = 21 ppm

i just put it in ratios, cos c1v1 = c2v2 will change the value
something seems wrong, may someone clarify please

 

[ibbi00]

i think so
210 mg/ 1000 mL : c2 / 100mL
c2 = 21 ppm

i just put it in ratios, cos c1v1 = c2v2 will change the value
something seems wrong, may someone clarify please

c1 = 210 mg/L
v1= 0.01 L
v2= 0.1 L

Since our concentration is mg/L we have to treat our volumes as such.

so c1v1=c2v2
210 X 0.01 = c2 X 0.1

c2= 21