Question #748ea

According to Dalton's Law of Partial Pressures, each gas will exert its own partial pressure in the chamber.

Since the temperature is constant, we can use Boyle's Law to calculate the partial pressure of each gas in the chamber.

The formula for Boyle's Law is

#color(blue)(|bar(ul(P_1V_1 = P_2V_2)|)#

Step 1. Calculate the partial pressure of neon in the chamber.

Boyle's Law can be rearranged to

#P_2 = P_1 × V_1/V_2#

#P_1 = "1005 torr"; V_1 = "0.625 L"#
#P_2 = color(white)(mm)"?"; color(white)(mm)V_2 = "4.25 L"#

∴ #P_2 = 1005 "torr" × (0.625 color(red)(cancel(color(black)("L"))))/(4.25 color(red)(cancel(color(black)("L")))) = "147.8 torr"#

Step 2. Calculate the partial pressure of helium in the chamber.

#P_1 = "1324 torr"; V_1 = "0.355 L"#
#P_2 = color(white)(mm)"?"; color(white)(mm)V_2 = "4.25 L"#

∴ #P_2 = 1324 color(white)(l)"torr" × (0.355 color(red)(cancel(color(black)("L"))))/(4.25 color(red)(cancel(color(black)("L")))) = "110.6 torr"#

3. Calculate the total pressure in the chamber.

#P_"tot" = P_"Ne" + P_"He" = "147.8 torr + 110.6 torr" = "258 torr"#

The pressure in the chamber is 248 torr.