Question

E) 3.3 104 A S M o ssolution of the weak acid HA at 250 °C has a pH of 535. The value of K, for HA is D) 3.0 . 10-5 18-10-5 A24.10-10 5) 20. 109 D) 49.104 19 The K for HON A) 9.10 29.10-10 What is the value of b, for ON- 20.10-5 Q4. 10-6 is 9. 10-10 E) 1.1 1) the ON /00007 Maqueous sodium cyanide solution at 25.0 Kb for N 10 D) 8.8 A) 2 17) A d -Low he is defined as a substance that A) deces when placed in Ho ince when placed in Ho a s a proto por D) increases when placed in H2O acts as a proto donor 18) of the following acids A) H2SO4 3) HCIO is not a strong adid HNO2 D) HC E) HNO3 19) Which one of the following is the weakest acid? A) HNO2 (K-45. 10-4) B) HONK, -49.10-10) HCIO (K, -3.0 10-8) D) HF (K-6.8 10-4) E) Acetic acid (K-18.10-5) 20 A 0.1 M aqueous solution of will have the lowest pH at 25.0'C. Naoa KC NH4C COACH A) Naoa B) KCI NHC D) Ca(OAch2 E) KCl and NHACI 21) Which of the following combinations of chemicals could be used to make a buffer solution? A) HCVH3PO4 B) HCI/NH3 NaOH/NH3 D) HCI/NaOH 22) What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH3CO2H with 25.00 mL of 0.050 M CHON? Assume that the volume of the solutions are additive and that Ka 1.8 x 10-5 for CH3COOH A) 4.74 B) 4.44 2.87 D) 5.05 A-3
  

Just give me the answers

Answer 1

HA(09) 3 Htcaq) + A (aq) Initial(M) é — соо , самае (м) о a tea tea Equilibrium (M) ((1-x) ca ea [C = Initial concentration of HA and a e's eits degree of disso- Now, pH = -log[H+] = 5:35 or [H+] = 10-5:35 – 4:467x10CM) CQ = 4.467 xjö 6 or 0:15a = 4.467 xio [C= 0.15 (M)] or a = 4.46 7 X10% = 2.978x10° Ka = [H+1(4). ed. coc = Coc2 0.45 0(2.978X18" 1- - 21978x105) = 1.33x1610 2. Ans & A 0.5 2978410 5,2 C 78XI0 [HA] (10)