Help please! A gas occupies 500 mL at 270 mm Hg and 55°C. If the pressure is changed to 1.8 atm and the temperature is increased to 100°C, what is the new volume? Be sure to show the setup and the final answer and unit.
Show Your Work

V₂ = 112.14 mL

Explanation:

Given data:

Initial volume = 500 mL

Initial pressure = 270 mmHg (270/760 =0.355 atm)

Initial temperature = 55 °C (55 +273 = 328 K)

Final temperature = 100°C (100+273 = 373 K)

Final volume = ?

Final pressure = 1.8 atm

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 0.355 atm × 500mL × 373 K / 328 K × 1.8 atm

V₂ = 66207.5 atm .mL. K /  590.4 K.atm

V₂ = 112.14 mL

air quality

poor drinking water

and heavy polution

can lead to poor health

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.