Help please! Assuming S. T.P., how many liters of oxygen when combined with excess sulfur dioxide are needed to produce 32.6 L of sulfur trioxide?

A) 0.728 L
B) 16.3 L
C) 32.6 L
D) 65.2 L

V = 16.3 L

Explanation:

Given data:

Volume of oxygen needed = ?

Temperature = standard = 273 K

Pressure = standard = 1 atm

Volume of sulfur trioxide = 32.6 L

Solution:

Chemical equation:

2SO₂ + O₂    →    2SO₃

Number of moles of SO₃:

PV = nRT

1 atm × 32.6 L = n×0.0821 atm.L/mol.K ×273 K

32.6 atm.L =n× 22.41 atm.L/mol

n = 32.6 atm.L / 22.41 atm.L/mol

n = 1.45 mol

now we will compare the moles of oxygen with sulfur trioxide.

                 SO₃        :        O₂  

                    2          :         1

                  1.45       :       1/2×1.45 = 0.725 mol

Volume of oxygen:    

PV = nRT

1 atm × V = 0.725 mol×0.0821 atm.L/mol.K ×273 K

V  = 16.25 atm.L /1 atm

V = 16.3 L

no, i was listening to water by schoolboy q while and i saw this question

explenation:

water isn't wet. wetness is a description of our experience of water; what happens to us when we come into contact with water in such a way that it impinges on our state of being. we, or our possessions, 'get wet'. a less impinging sense experience of water is that it is cold or warm, while visual experience tells us that it is green or blue or muddy or fast-flowing. we learn by experience that a sensation of wetness is associated with water: 'there must be a leak/i must have sat in something.'

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.