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# Hello! I got two problems that I require help. watch

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1. 1. The amount of sulfur emitted into the atmosphere in ayear by burning coal is 75 million tonnes. Assuming that the entire quantity ofsulfur is solid state, how much volume will occupy sulfur (sulfur attributed toa quantity of a building)? (Density S = 2 g / cm3).
2. SO2 and SO3 is released into the environment from variousindustrial activities. Considering that these two oxides of sulfur are the onlysource of pollution as a result of industrial activities, was collected a stample of 20 liters air in normal conditions. It was bubbled through 100 mLH2O2 concentration c = 2.4 * 10-3 mol / L. After completion of bubbling, thesolution was treated with BaCl2, resulting 105.6 mg precipitat.The excess ofH2O2 is titrated with a solution containing 15.9 mg K2Cr2O7. Determine the concentrations expressed in g oxide / m3 air for that two oxides present in the air- SO2 and SO3.
2. (Original post by Savvan)
1. The amount of sulfur emitted into the atmosphere in ayear by burning coal is 75 million tonnes. Assuming that the entire quantity ofsulfur is solid state, how much volume will occupy sulfur (sulfur attributed toa quantity of a building)? (Density S = 2 g / cm3).
2. SO2 and SO3 is released into the environment from variousindustrial activities. Considering that these two oxides of sulfur are the onlysource of pollution as a result of industrial activities, was collected a stample of 20 liters air in normal conditions. It was bubbled through 100 mLH2O2 concentration c = 2.4 * 10-3 mol / L. After completion of bubbling, thesolution was treated with BaCl2, resulting 105.6 mg precipitat.The excess ofH2O2 is titrated with a solution containing 15.9 mg K2Cr2O7. Determine the concentrations expressed in g oxide / m3 air for that two oxides present in the air- SO2 and SO3.
This is my attempt for problem no.2 :
I used equivalence law:...But I don't know to solve the problem from chemical reactions.
E K2Cr2O7 = M/6 = 294/6 = 49
15,9 mg K2Cr2O7 = 15,9 * 10-3 g K2Cr2O7 => E K2Cr2O7 =M/49 = 15,9 * 10-3 / 49 = 3,24 * 10-4 ( equivalent K2Cr2O7) =>
-> 3,24 * 10-4 equivalent H202 => 2* 2,4 * 10-4 equiv. H2O2 = 4,8 * 10-4 E H2O2 =>
2,4 * 10-4 mol H2O2
E H2O2 = M/2
-> 4,8-3,24 = 1,56 * 10-4 E H2O2 => 1,56 * 10-4 E SO2 => 2 * 1,56 = 3,2 * 10-4 mol SO2
M SO2= 3,2 * 10-4 * 64g = 0,12 g SO2
E SO2 = M/2

M BaSO4=233 g/mol, 105,6 mg BaSO4 =105,6 * 10-3 g BaSO4 ->4,5 * 10-4 mol -> 3,2 * 10-4 mol SO2 and 1,3 * 10-4 mol SO3

M SO3 = 80 g/mol
m SO3 = 1,3 * 10-4 * 80 = 0,104 g.

20L air ..0,12g SO2....0,104g SO3
1000L air (1m3)..x g....y g

x=200/20 = 10 g SO2 m3 ... and y=5,2g SO3 m3
3. (Original post by Savvan)
1. The amount of sulfur emitted into the atmosphere in ayear by burning coal is 75 million tonnes. Assuming that the entire quantity ofsulfur is solid state, how much volume will occupy sulfur (sulfur attributed toa quantity of a building)? (Density S = 2 g / cm3).
2. SO2 and SO3 is released into the environment from variousindustrial activities. Considering that these two oxides of sulfur are the onlysource of pollution as a result of industrial activities, was collected a stample of 20 liters air in normal conditions. It was bubbled through 100 mLH2O2 concentration c = 2.4 * 10-3 mol / L. After completion of bubbling, thesolution was treated with BaCl2, resulting 105.6 mg precipitat.The excess ofH2O2 is titrated with a solution containing 15.9 mg K2Cr2O7. Determine the concentrations expressed in g oxide / m3 air for that two oxides present in the air- SO2 and SO3.
75 million tonnes = 7.5 x 1013 grams

If sulfur has a density of 2 g/cm3

Then the number of cm3 = 3.75 x 1013 cm3
4. Thank you!! But is 7.5 x 1012, isn't it ?

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Updated: February 29, 2016
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