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As the [H_3O^+] in a solution decreases, the [OH^-] A. increases and the pH incr

ID: 506465 • Letter: A

Question

As the [H_3O^+] in a solution decreases, the [OH^-] A. increases and the pH increases. B. increases and the pH decreases. C. decreases and the pH increases, decreases and the pH decreases. The pH meter is in the lab was standardized with ____ A. A pH 7 solution B. A pH 0 solution C. Litmus Paper D. Methyl Orange Indicator What is the [H_3O^+] in 0.025M HNO_3? A. 4.0 times 10^-13 M B. 0.025 M C. 1.60 M D. 12.40 M A basic solution can be defined as one in which A. [H_3O^+] is not present B. [H_3O^+] is equal to [OH^-] C. [H_3O^+] is less than [OH^-] D. [H_3O^+] is greater than [OH^-] For the reaction A + B rightarrow C + D, Delta H degree = +40 kJ and Delta S degree = +50 J/K. Therefore, the reaction under standard conditions is..? A. spontaneous at temperatures less than 10 K B. spontaneous at temperatures greater than 800 K C. spontaneous only at temperatures between 10 K and 800 K D. spontaneous at all temperatures

Explanation / Answer

13.Option A

As [H+] decreases , the [OH-] increases and thus the pH also increases.

14) pH meter is calibrated with pH = 7 solution..

15)

The {H3O+] in 0.025M strong acid HNO3 = 0.025 M only

16) A basic solution is defined as the one in which [H3O+] < [OH]-

17) The reaction is endothermic.

and T of equilibrium = delta H / delta S

= 40x1000J /50J

= 800 K

Thus the reaction is spontaneous above 800K