Chemical reactions:
A. only break chemical bonds or form them but never in the same reaction.
B. are written with the product on the left and the reactant on the right with an arrow to indicate the direction of the reaction.
C. proceed spontaneously through a low-energy transition state to product.
D. proceed spontaneously if the free energy of the product is greater than that of the reactant.
E. require collisions between reactants, therefore the reaction rate increases when the concentration of the reactants is greater.
Nucleophilic attack:
A. is carried out by a strongly electronegative atom such as carbon or hydrogen.
B. can result in the formation of the transition state of the reaction.
C. by an OH (hydroxyl) group on an inorganic phosphate molecule can cause hydrolysis of a chemical bond.
D. occurs when a weakly electronegative atom attacks a strongly electronegative atom.
E. never forms bonds between reactants and the enzyme active site.
Each weak acid has a characteristic pKa value defined as pKa = -logKa. What does the pKa tell you about the composition of the acid solution?
What will be an ideal response?
A 200-ml solution of 0.5 M lactic acid was adjusted to a pH of 3.6 . If you add 20 ml of 2.0 M NaOH what will the pH of the solution be? The pKa of lactic acid is 3.6.
A. 4.6
B. 3.6
C. 3.0
D. 2.6
E. 2.0
If 0.08 mol of phenol and 0.03 mol of NaOH are combined in a total volume of 0.1 L, what would be the pH of the solution? The pKa of phenol is 9.9.
A. 10.5
B. 8.5
C. 9.5
D. 9.7
E. 9.9
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