Problem page a gas made up of atoms escapes through a pinhole 0.225 times as fast as h2 gas. write the chemical formula of the gas.

)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.

If volume remains the same while the mass of a substance the density of the substance

Select all that apply. when the products of a reaction have less energy than the reactants: the reaction is exothermic. the reaction is endothermic. the reactants lost internal energy. the change in enthalpy is positive.