2. If an endorthermic reaction is spontaneous at 298 K, which of the following must be true for the reaction?
DG is greater than zero DG is greater than zero DG and DH are greater than zero DH and DS are greater than zero DG, DH, DS are all greater than zero
3. For the dissociation reaction of the acid HF: HF<-->H++ F -DS is observed to be negative. The BEST explanation for this is:
This is the expected result since each HF molecule produces two ions when it dissassociates Hydration of the ions produces the negative value of DS. The reation is expected to be exothermic and thus D should be negative. The reaction is expected to be endothermic and thus D should be negative. None of these can explain the negative value of DS.
4. Which of these statements is false?
For a spontaneous reaction DG is negative Independent of T, a reaction must be spontaneous if DH = 0 and DS is positive A spontaneous reaction is always fast A spontaneous reaction occurs without outside intervention None of the above is false
5. For the gas sample B, this reaction is endothermic: B-->2B. The reaction is:
always spontaneous only at high temperatures only at low temperatures never spontaneous none of the above
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