We can use the Ideal Gas Law to calculate the partial pressures.

#color(blue)(bar(ul(|color(white)(a/a)pV = nRTcolor(white)(a/a)|)))" "#

or

#p = (nRT)/V#

The number of moles #n# is given by

#n = m/M#

So,

#p = (mRT)/(MV)#

**Calculate #p_text(O₂)#**

#m color(white)(l)= "7.67 g"#

#Rcolor(white)(l) = "0.082 06 L·atm·K"^"-1""mol"^"-1"#

#Tcolor(white)(l) = "65 °C" = "338.15 K"#

#M = "32.00 g·mol"^"-1""#

#V color(white)(l)= "9.77 L"#

∴ #p = (7.67 color(red)(cancel(color(black)("g"))) × "0.082 06" color(red)(cancel(color(black)("L")))·"atm"color(red)(cancel(color(black)("·K"^"-1""mol"^"-1"))) × 338.15 color(red)(cancel(color(black)("K"))))/(32.00 color(red)(cancel(color(black)("g·mol"^"-1"))) × 9.77 color(red)(cancel(color(black)("L")))) = "0.681 atm"#

**Calculate #p_text(Ne)#**

#m color(white)(l)= "2.84 g"#

#Rcolor(white)(l) = "0.082 06 L·atm·K"^"-1""mol"^"-1"#

#Tcolor(white)(l) = "65 °C" = "338.15 K"#

#M = "20.18 g·mol"^"-1""#

#V color(white)(l)= "9.77 L"#

∴ #p = (2.84 color(red)(cancel(color(black)("g"))) × "0.082 06" color(red)(cancel(color(black)("L")))·"atm"color(red)(cancel(color(black)("·K"^"-1""mol"^"-1"))) × 338.15 color(red)(cancel(color(black)("K"))))/(20.18 color(red)(cancel(color(black)("g·mol"^"-1"))) × 9.77 color(red)(cancel(color(black)("L")))) = "0.3997 atm"#

**Calculate the total pressure**

#p_text(tot) = p_text(O₂) + p_text(Ne) = "(0.681 + 0.3997) atm" = "1.081 atm"#