# Problem: Consider the following reaction sequence for the determination of dissolved oxygen in water:   2MnSO4(aq) + 4NaOH(aq) + O 2(aq) → 2MnO2(s) + 2Na2SO4(aq) + 2H2O(l) MnO2(s) + 2H2SO4(aq) + 2NaI(aq) → MnSO 4(aq) + I 2(aq) + Na 2SO4(aq) + 2H 2O(l) I2(aq) + 2Na 2S2O3(aq) → Na 2S4O6(aq) + 2NaI(aq)   If 9.00 mL of 0.0240 M Na 2S2O3(aq) are used in the analysis, how many moles of dissolved oxygen were determined? a) 4.32 x 10-4 mol b) 2.70 x 10-5 mol c) 5.40 x 10-5 mol d) 2.16 x 10-4 mol e) 1.08 x 10-4 mol

###### FREE Expert Solution
87% (417 ratings)
###### Problem Details

Consider the following reaction sequence for the determination of dissolved oxygen in water:

2MnSO4(aq) + 4NaOH(aq) + O 2(aq) → 2MnO2(s) + 2Na2SO4(aq) + 2H2O(l)

MnO2(s) + 2H2SO4(aq) + 2NaI(aq) → MnSO 4(aq) + I 2(aq) + Na 2SO4(aq) + 2H 2O(l)

I2(aq) + 2Na 2S2O3(aq) → Na 2S4O6(aq) + 2NaI(aq)

If 9.00 mL of 0.0240 M Na 2S2O3(aq) are used in the analysis, how many moles of dissolved oxygen were determined?

a) 4.32 x 10-4 mol

b) 2.70 x 10-5 mol

c) 5.40 x 10-5 mol

d) 2.16 x 10-4 mol

e) 1.08 x 10-4 mol

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Solution Stoichiometry concept. You can view video lessons to learn Solution Stoichiometry. Or if you need more Solution Stoichiometry practice, you can also practice Solution Stoichiometry practice problems.

What is the difficulty of this problem?

Our tutors rated the difficulty ofConsider the following reaction sequence for the determinati...as high difficulty.

How long does this problem take to solve?

Our expert Chemistry tutor, Jules took 5 minutes and 55 seconds to solve this problem. You can follow their steps in the video explanation above.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Hoeger's class at UCSD.