What is the concentration in molarity of S2O32- (aq) in a solution prepared by mixing 300 mL of 0.162 M Na2S2O3 (aq) with enough 0.126 M KCl (aq) to make a 350.0 mL solution? (Assume volumes are additive and that no chemical reactions take place.)

Question

What is the concentration in molarity of S2O32- (aq) in a solution prepared by mixing 300 mL of 0.162 M Na2S2O3 (aq) with enough 0.126 M KCl (aq) to make a 350.0 mL solution? (Assume volumes are additive and that no chemical reactions take place.)

1 Answer

Impact of this question

13417 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-02-23T01:02:40

${[N a_{2} C_{2} O_{3}]}_{final}$ $[Na_2C_2O_3]_"final"$ = $0.139 M$ $0.139M$

Explanation:

If no reaction takes place (which is true in the case noted), you're simply diluting the concentrate to (30/35)th of it's original concentration to give a $\frac{30}{35} \times 0.162 M$ $(30)/(35)xx0.162M$ = 0.139M Solution of $N a_{2} S_{2} O_{3}$ $Na_2S_2O_3$ .

In solution, the thiosulfate ion concentration will be equal to the final concentration of the diluted sodium thiosulfate because it's a 1 to 1 ionization ratio. That is,

$N a_{2} S_{2} O_{3}$ $Na_2S_2O_3$ => $2 N a^{+} (a q)$ $2Na^+(aq)$ + $S_{2} O_{3}^{2 -} (a q)$ $S_2O_3^(2-)(aq)$
$(1 mole)$ $("1 mole")$ $\times \times (2 mole)$ $color(white)(xxxx)("2 mole")$ $\times x (1 mole)$ $color(white)(xxx)("1 mole")$

For determining concentration of diluted solution, one may also use 'The Dilution Equation' => Molarity x Volume of Concentrated Solution = Molarity x Volume of Diluted Solution, or ...

${(M o l a r i t y \times V o l u m e)}_{concentrate}$ $(Molarity xx Volume)_"concentrate"$

= ${(M o l a r i t y \times V o l u m e)}_{diluted}$ $(Molarity xx Volume)_ "diluted"$

$(0.162 M) (300 m l)$ $(0.162M)(300ml)$ = $[S_{2} O_{3}^{2 -}] (350ml)$ $[ S_2O_3^(2-)]"(350ml)"$

=> $[S_{2} O_{3}^{2 -}]$ $[S_2O_3^(2-)]$ = $(0.162M)(300cancel(ml))/(350cancel(ml))$ = $0.139M$

Science

Math

Humanities

... and beyond

What is the concentration in molarity of S2O32- (aq) in a solution prepared by mixing 300 mL of 0.162 M Na2S2O3 (aq) with enough 0.126 M KCl (aq) to make a 350.0 mL solution? (Assume volumes are additive and that no chemical reactions take place.)

1 Answer

Explanation:

Related questions

Impact of this question