Data for permeation of a gas species through a solid are often presented in terms of a socalled permeation constant k, which is defined as the product of the solubility constant and the diffusivity: k = bdab. it is commonly expressed as the amount of gas [cm3/s at stp (273k and 1 atm)] permeating through a 1 cm2 cross section of solid of 1 cm thickness, for a partial pressure difference of 1 atm. for hydrogen through pyrex glass at 1000 k, k = 1.2 x 10^-8 cm^2/s∙atm and dab = 2 x 10^-8 cm^2/s. find the solubility of hydrogen in glass, in mass fraction units (i. e., grams of h2 per gram of glass per atmosphere partial pressure). take the density of the glass to be 2.4 g/cm3.

The density would be 1.622

Answerthis solution will not form a precipitateexplanationsolubility equilbrium:         pbf₂(s)  ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is    (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as    then, we can interpret  q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually  forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product:     since q = 2.7  × 10⁻⁸ < ksp =  4  ×  10⁻⁸, a precipitate will not form.

Answer two atoms of oxygen;