Question

Sodium thiosulfate (Na2S2O3), photographer’s

Answer 1

Answer:

0.30 moles of sodium thiosulfate formula units are needed to make 0.10 moles of AgBr soluble.

Explanation:

$3Na_2S_2O_3+AgBr\rightarrow NaBr+Na_5[Ag(S_2O_3)_3]$

According to reaction , 1 mole of silver bromide dissolves in 3 moles of Sodium thiosulfate .

Then 0.10 moles of AgBr will dissolve with:

$\frac{3}{1}\times 0.10 mol=0.30 mol$

0.30 moles of sodium thiosulfate formula units are needed to make 0.10 moles of AgBr soluble.

Answer 2

3Na2S2O3 + AgBr ------>Na5[Ag(S2O3) 3] +NaBr

from equation 3 mol 1 mol

given x mol 0.10 mol

x= (3*0.10)/1=0.30 mol Na2S2O3

Answer: 0.30 mol Na2S2O3