Question

What is the pH of the solution which results from mixing 35 mL of 0.50 M NH₃(aq) and 35 mL of 0.50 HCl(aq) at 25 °C? (K_b for NH₃ = 1.8 ´ 10^-5

	0.60
	2.67

	4.74
	4.93

9.26

What is the pH of the buffer that results when 11 g of NaCH₃CO₂ is mixed with 85 mL of 1.0 M CH₃CO₂H and diluted with water to 1.0 L? (K_a of CH₃CO₂H = 1.8 ´ 10^-5)

	2.91
	3.86

	4.55
	4.74

4.94

If a process is exothermic and spontaneous, which of the following must be true?

	DG > 0 and DH < 0
	DG < 0 and DH < 0

	DG < 0 and DS > 0
	DH < 0 and DS > 0

DH > 0 and DS < 0

At what temperatures will a reaction be spontaneous if DH = -76.0 kJ and DS = +231 J/K?

	All temperatures below 329 K
	Temperatures between 0 K and 231 K

	All temperatures above 329 K
	The reaction will be spontaneous at any temperature.

The reaction will never be spontaneous.

The pH of aqueous 0.050 M trimethylamine is 11.24. What is the K_b of this base?

	6.6 ´ 10-22
	5.8 ´ 10-12

	6.3 ´ 10-5
	1.7 ´ 10-3

2.76