At an atmospheric pressure of 749 mmHg, the volume of a helium balloon is 3,690mL. What would this volume be at standard temperature?

Find the mass in grams of hydrogen gas produced when 14.0 moles of hcl is added to an excess amount of magnesium.

Which metal exist in liquid state and can be cut with knife ?

)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.