Question

6. On the diagram at the right of titration of a weak acid by a strong base, what is represented by the point A? A. the 50:50 buffer mixture B. the stoichiometric point C. mL added base D. the buffer zone E solution of strong base 7. Which of the following has the best buffer capacity? A. 0,2 M NH /0.2 M NHẠC B. 0.5 M HCI/O.5 M KCI C. 1.0 M HCI/1.0 M NACI D. 1.0 M HCI/1.0 M NaOH E.0.5 M NaH,PO/0.5 M NazHPO. 8. If the Ka for nitrous acid is 4.3x104, then what is the pH of a 0.30 M HNO./0.20 M KNO2 solution? A. 3.67 B. 3.19 C.3.07 D. 3.54 E. 3.37 _9. The Ksp expression for Cu(OH)2 is A. [Cu](OH) B. [Cu2+][OH-] C. (Cu ][20H) D. [Cu?"| [OH-]*[Cu(OH)2] E. (Cu2+1" [OH1/[Cu(OH)2] 10. Which of the following will result in an INCREASE in the entropy of the system? A. heat flowing from cold to hot B. a gas compressing C. a gas condensing to a liquid D. a solid melting

Answer 1

Answor i Dr. The buffer zone At highlighted point the solution how they a showing common in effect therefore it acts as a buffer then it i i called buffer zone 7) Answer'-E), 0.51 NaH, PO4 / 0.5 M NasH POL bring in the above solution the concentration of com are more those fore it acts as a good butter others GUM Nit; 10.2m Nhild is buffer but not concentration is low, ®e © are not acts as a buffer. The buffer means werk aud & ith salt a weak base and in salt (conjugate base) 0130M HNO2 + 0.2014 KNOG - Acid salt 8) put s plan to longe pH = -lag (ka) + log Call put = -by (41,3 x 54) t congestion Pro - 0.176 pH 3.367 pH = 3.191 Answer B? 3.19

91. Ca (OH) > Cu2t + 2011 - Ksp= [cu?t] [ot] 1 (CuOHh] Armouse [cu"] Cow I° /60 (01)] los. d) a solid melting O Entropy increasing order means a randommes going to increases. The solid Hole iono are strongly held & regularly arranged the it melts become a liquid it becomes innegular so for that entropy increases solid < Liquid < gas or a solid melting. Amiway