Find the pH of 0.175 M NaCN solution. For HCN, Ka = 4.9 × 10-10. ( )
A. 5.03
B. 11.28
C. 2.31
D. 8.97
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For a process to occur spontaneously, ( )
A. the entropy of the system must increase
B. the entropy of the surroundings must increase
C. both the entropy of the system and the entropy of the surroundings must increase
D. the net change in entropy of the system and surroundings considered together must be a positive quantity
Which process results in the increase in entropy of the universe? ( )
A. the cooling of a hot cup of coffee in room temperature air
B. the evaporation of water from a desk at room temperature
C. the melting of snow above 0 °C
D. all of the above
Of the following, the amphoteric ion is ( )
A. HCO3-
B. CO32-
C. NH4+
D. ClO4-
1.56 mM equals to ( )? ( )
A. 1560 M
B. 1.56 x 103M
C. 1.56 x 10-3 M
D. 0.156 M
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