Question #46508

1 Answer
Aug 3, 2017

#"pressure" = 554# #"torr"#

Explanation:

We're asked to find the original pressure of the gas, given its initial and final temperatures, and the final pressure.

To do this, we can use the Gay-Lussac's law equation:

#(P_1)/(T_1) = (P_2)/(T_2)#

where

  • #P_1# is the original pressure (what we're trying to find)

  • #T_1# is the original absolute temperature, which must be in Kelvin:

#150# #""^"o""C"# #+ 273 = ul(423color(white)(l)"K"#

  • #P_2# is the final pressure (#456# #torr"#)

  • #T_2# is the final temperature, which is

#75.0# #""^"o""C"# #+ 273 = ul(348color(white)(l)"K"#

Let's rearrange the equation to solve for the unknown, #P_1#:

#P_1 = (T_1P_2)/(T_2)#

Plugging in known values, we have

#P_1 = ((423cancel("K"))(456color(white)(l)"torr"))/(348cancel("K")) = color(red)(ulbar(|stackrel(" ")(" "554color(white)(l)"torr"" ")|)#