A1-m depth of stagnant water lies on top of a 0.35 cm thickness of nacl. at time t < 0, the water is pure. at time t 0, the salt begins to dissolve into the water. if the concentration of salt in the water at the solid-liquid interface is maintained at saturation (0.00685 mol nacl/cm3) and the diffusivity of nacl is 2.3c-005 cm2/s, independent of concentration, estimate, by assuming the water to act as a semi-infinite medium, the time of salt in the water when: (a) 10% of the salt has dissolved; ; (b) 50% of the salt has dissolved, and (c) 90% of the salt has dissolved. density of nacl 2.165 g/cm3. molecular weight of nacl 58.44 g/mol.

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.