Question

Consider the system introduced in example 3.B.2 (p. 97) in which a 2 L sealed jar, half filled with water and half filled with air, contains 10-3 mol of toluene. The equilibrium partitioning is described by Henry's law, so that the aqueous phase contains 0.78 x 10-3 mol and the gas phase contains 0.22 x 10-3 mol. To this system 150 mg of activated carbon is added to absorb toluene. Toluene partitioning between the sorbed and aqueous phases is described by the Freundlich isotherm qe = 100Ce0.45 (see example 3.B.5, p. 103 for clearer notation of this equation), where Ce is the aqueous concentration in mg/L and qe is the sorbed mass concentration in mg toluene per g activated carbon. What can you say about the new equilibrium concentration of toluene in water?

Answer 1

Ans-

a. Polarity is a term applied to covalent compounds. Polar co-
valent compounds have an unequal sharing of electrons in bonds
that results in unequal charge distribution in the overall molecule.
Polar molecules have a partial negative end and a partial positive
end. These are not full charges as in ionic compounds but are
charges much smaller in magnitude. Water is a polar molecule and
dissolves other polar solutes readily. The oxygen end of water (the
partial negative end of the polar water molecule) aligns with the
partial positive end of the polar solute, whereas the hydrogens of
water (the partial positive end of the polar water molecule) align
with the partial negative end of the solute. These opposite-charge
attractions stabilize polar solutes in water. This process is called
hydration. Nonpolar solutes do not have permanent partial negative
and partial positive ends; nonpolar solutes are not stabilized in
water and do not dissolve. b. KF is a soluble ionic compound.

As reactants are converted to products, the
moles of gas particles present decrease by one-half. As n decreases,
the pressure will decrease (by one-half). Density is the mass per unit
volume. Mass is conserved in a chemical reaction, so the density
of the gas will not change since mass and volume do not change.
Flexible container (constant pressure): Pressure is constant since
the container changes volume to keep a constant pressure. As the
moles of gas particles decrease by a factor of 2, the volume of the
container will decrease (by one-half).