18. A 0.405-g sample of NaOH(s) is added to enough water to make 250.0 mL of solution. The pH of this solution is:A) 1.393B) 0.393C) 12.005D) 12.607E) none of these19. Approximately how much water should be added to 10.0 mL of 12.4 M HCl so that it has the same pH as 0.90 M acetic acid (Ka= 1.8 10-5)?20. Given the equation A(aq) + 2B(aq) <===>3C(aq) + 2D(aq). 45.0 mL of 0.050 M A is mixed with 25.0 mL 0.100 M B. At equilibrium the concentration of C is 0.0410 M. Calculate K.21. Calculate the pH of the following aqueous solution:0.74 M NaF (pKafor HF = 3.14)Page 6
22. If, at a given temperature, the equilibrium constant for the reaction H2(g) + Cl2(g) <===>2HCl(g) is Kp, then the equilibrium constant for the reaction HCl(g) <===>H2(g) + Cl2(g) can be represented as:Use the following to answer question 23.Consider the following equilibrium: 2NOCl(g) <===>2NO(g) + Cl2(g) with K= 1.6 ×10–5. 1.00 mole of pure NOCl and 1.00 mole of pure Cl2are placed in a 1.00-L container.23. If xmoles of NOCl react, what is the equilibrium concentration of NO?24. The pH of a solution at 25°C in which [OH-] = 3.9 ×10-5 M is:Page 7
25. What quantity of NaOH(s) must be added to 2.00 L of 0.533 M HCl to achieve a pH of 13.00? (Assume no volume change.)A) 0.87 molB) 1.27 molC) 0.20 molD) 1.00 ×10-13molE) none of these26. At 500.0 K, one mole of gaseous ONCl is placed in a one-liter container. At equilibrium it is 5.1 % dissociated according to the equation shown here: 2ONCl <===>2NO + Cl2. Determine the equilibrium constant.