(i)What is the free energy of mixing I g of polystyrene of molar mass M = lif gmol- 1• with I mol of cyclohexane at 34 °C?Note that 34 °C is the 0-temperature for a polystyrene solution in cyclohexane (Flory inter­action parameter x = 1/2). The molar volume of polystyrene is vp, = 9.5 x 104 cm3 mo1- 1, the molar volume of cyclohexane is Vcyc= 108cm3 mol - 1• Assume no volume change upon mixing and assume that the volume of one solvent molecule is the lattice site volume v0.(ii)What does the sign of the free energy of mixing imply about the stability of a homogeneous solution?(iii)Under what conditions does the homogeneous solution spontaneously phase separate by spinodal decomposition?(iv)When is the homogeneous solution metastable?

In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. the solution was heated by burning natural gas in a bunsen burner to distill the ethanol that formed in the flask. during the distillation, the ethanol evaporated and then condensed in the receiving flask. the flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. during this experiment the following changes occurred. which of these changes involved a physical change and not a chemical change? check all that apply. 1-condensation of ethanol 2-evaporation of ethanol 3- formation of carbon dioxide gas from glucose burning of natural gas 4-formation of ethanol from glucose by yeast 5-formation of a carbon deposit inside the flask

Balance and in which category does it fit in? single or double displacement or synthesis or decomposition? (a) k2 o → k + o2 (b) na + i2 → nai (c) cu(no3 )2 + naoh → cu(oh)2 + nano3 (d) kclo3 → kcl + o2 (e) ca(no3 )2 + hbr → cabr2 + hno3 (f) sn(oh)2 → sno + h2 o (g) p4 + n2 o → p4 o6 + n2 (h) fe + al2 (so4 )3 → feso4 + al (i) alcl3 + na2 co3 → al2 (co3 )3 + nacl (j) c3 h6 + o2 → co2 + h2 o

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space