Question

Reactions 1-4 below describe the industrial process used to synthesize sulfuric acid starting from sulfur, oxygen gas, and water.

Reaction 1:    S(s) + O2(g) → SO2(g)

Reaction 2: 2 SO2(g) + O2(g)  → 2 SO3(g)

Reaction 3: H2SO4(l) + SO3(g) → H2S2O7(l)

Reaction 4: H2S2O7(l) + H2O(l) → 2 H2SO4(l)

Overall Reaction (1-4): 2 S(s) + 3 O2(g) + 2 H2O(l) → 2 H2SO4(l)

A. The industrial production of sulfuric acid involves proper control of temperatures and flow rates of the gases to generate the highest percent yield possible.

Consider a scenario where Reaction 1 suffers from a 70.0 % yield followed by a dismal yield of 30.0 % in Reaction 2. If the remaining reactions are highly efficient (100% conversion), what would be the yield for the overall reaction to convert sulfur to sulfuric acid (see Reactions 1-4 above)

Overall Yield=____

B.   Assuming the production of the final product is limited to the percent yield calculated in part A above, how many tons of solid sulfur would be needed to generate 2.00 x 108tons of sulfuric acid?

Reference information:

1.000 ton = 2000. pounds

1 pound = 453.592 g

Express the final answer using scientific notation with the format:

Y x 10z tons

Y= ____

Z=____

Answer 1

Let us take 100 moles initially

In first step 70.0 % yield we will get

If we start with 100 moles for 70% yield we will 70 Moles

In second step Reaction 2 for 30% yield we will 21 Moles (30x70/100).

In other 2 steps 100 % yield

Hence 21 Moles we will get.

Hence we started with 100 Moles and end up with 21 Moles. So Overall yield is 21 %

Quesion B

2.0 x 10⁸ tons of sulfuric acid =2 x 10⁸ / 98 = 2.040 x 10⁶ Moles tons

Over all yield is 21%

We need 100 x 2.04 x 10⁶ x 32  /21 = 3.10 x 10⁸ tons of sulfur is need