A 350 mL sample of air collected at 35°C has a pressure of 550 torr. What pressure will the air exert if it is allowed to expand to 425 mL at 57°C?

1 Answer
Jun 17, 2017

Answer:

#485# #"torr"#

Explanation:

We can solve this equation using the combined gas law:

#(P_1V_1)/(T_1) = (P_2V_2)/(T_2)#

Remember, always use the absolute (Kelvin) temperature when working with gas equations.

The temperature conversions are

#T_1 = ""^"o""C" + 273 = 35^"o" + 273 = color(red)(308# #color(red)("K"#

#T_2 = 57^"o""C" + 273 = color(green)(330# #color(green)("K"#

Since we're trying to find the final pressure, let's rearrange this equation to solve for #P_2#:

#P_2 = (P_1V_1T_2)/(T_1V_2)#

Our known values:

#P_1 = 550# #"torr"#

#V_1 = 350# #"mL"#

#T_1 = color(red)(308# #color(red)("K"#

#V_2 = 425# "#mL"#

#T_2 = color(green)(330# #color(green)("K"#

Let's plug these into the equation to find the final pressure:

#P_2 = ((550"torr")(350cancel("mL"))(330cancel("K")))/((308cancel("K"))(425cancel("mL"))) = color(blue)(485# #color(blue)("torr"#

The final pressure after it is subjected to these changes is thus #color(blue)(485# #sfcolor(blue)("torr"#.