If the titration of 25.0 ml. of Hall requires 34.45mL of .100 M C a(OH)_2, what
ID: 1020687 • Letter: I
Question
If the titration of 25.0 ml. of Hall requires 34.45mL of .100 M C a(OH)_2, what is the molarity of the acid? 2HCl + Ca(OH)_2 rightarrow CaCl_2 + 2 H_2O .138M .0726M .276M .138M None of the above As the pH changes from pH=4 to pH=2, the H+ ion concentration decreases 20x the H+ ion concentration decreases 100x the H+ ion concentration increases 20x the H+ ion concentration increases 100x none of the above Calculate the pH of a .0004M H^+ solution. 10^-4 -3.4 3.4 1.0 None of the above For questions 44-46 Use the following chemical equation and answers:Predict the direction of equilibrium shift for the following stresses in the following reaction:CH_4(g) + H_2O(g) leftarrow rightarrow CO(g) + 3H_2(g) shift left shift right no effect If the concentration of [CH_4] decreases, the reaction will If the reaction is exothermic and the temperature is increased, the reaction will If the volume of the container is increased, the reaction will What is the oxidation number for S in sulfate ion. SO_4^2-? +2 -4 +6 -8 None of the aboveExplanation / Answer
41. Molarity of HCl = 0.1 M x 34.45 ml x 2/25 ml = 0.276 M
Answer : c) 0.276 M
42. As pH changes from pH = 4 to pH 2,
d. The H+ ion concentration increases by 100x
43. pH = -log[H+] = -log[0.0004] = 3.4
Answer : c) 3.4
44. When [CH4] concentration decreases, the reaction will a) shift left
45. When the temperature of exothermic reaction is increased, the reaction will a) shift left
46. If volume of container is increased, the reaction will b) shift right
47. Oxidation number of S in SO4^2- is,
c) +6