A sample of 7.55 g of He has a volume of 5,520 mL and a temperature of 123°C. What is its pressure in torr?

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?

Light waves can move through , but they travel fastest when they move through a(n) .

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.