Question

multiple choice for 1-8

1. The length of a hydro gen bond is given as the distance between A) the donor atom and the hydrogen atom; B) the acceptor atom and the donor atom; C) the hydrogen atom and the acceptor atom; D) none of these 2. The melting point of a pure solid (X) is 1 °C. This chemical is not soluble in water If you placed a crystal of this solid into a beaker of water at 2 °C A) the crystal will float; B) the crystal will sink; C) the free energy change for XX would be negative; D) the free energy change for XX wOuld be positive; E) the free energy change for XX would be zero. 3. The strength of the Coulombic interaction between two ions exactly 4 Angstroms apart in water will be A) 80-times greater than the interaction in a vacuum; B) 80- times weaker than the interaction in a vacuum; C) the same strength as the interaction in a vacuum; D) 320-times weaker than the interaction in a vacuum. 4. You prepare a solution by diluting concentrated HCl to a final concentration of 0.8 X 0 M in water. The pH of the solution would be equal to: A) -log[1.8 X 10 ]; B) log[1.08 X 10*; C)-log[1.0 X 107); D) None of these S. 2 pts. A certain volume of 1.0 M NaOH is needed to titrate 500 mL of a 0.2 M so lution of a weak acid (pKa 4.0) to the equivalence point. You then titrate a 0.4 M so lution of this same weak acid but to pH=4,0. If you used the same amount of 1.0 M NaOH for the second titration as for the first, the volume of 0.4 M solution titrated is: A) 100 mL; B) 250 mL; C) 500 mL; D) 1000 ml: E) 200 mL 6. Divalent metal ions such as Mg2 are important in cells because they stabilize nucleic bases. A) True B) False 7. You would predict that the dipole moments of para-dichlorob enzene and 1,3,5 trichlorobenzene are equal. A) True B) False 8. In a plot of the linear functions describing the values of "TAS" and "AH" vs. temperature for the melting of pure sucrose (table sugar), the two functions will have equal values: A) at 0 °C; B) at some temperature above 0°C; C) at some temperature below 0 C; D) at all temperatures; E) the values are never equal

Answer 1

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