The solute in a 500mL bottle labeled 0.18 M HCI is; the solvent is; and the numb
ID: 1018740 • Letter: T
Question
The solute in a 500mL bottle labeled 0.18 M HCI is; the solvent is; and the number of moles of H_3O^+ is a. hydrochloric acid, water, 0.18 moles b. water, hydrochloric acid, 0.18 moles c. hydrochloric acid, water, 0.09 moles d. water, hydrochloric acid, 0.09 moles. The mole fraction of benzene (moles benzene/total moles) in a solution that is prepared from 150 grams of toluene (C_7H_g(l)) and 150 grams of benzene (C_6H_6(l)) a. Is more than the mole fraction of toluene b. The same as the mole fraction of toluene c. Is less than the mole fraction of toluene What is the net ionic equation when 50 ml of silver nitrate is mixed with 50 ml of iron (III) chloride? (Recall the solubility rules - nitrates are soluble, chlorides are soluble except for silver, lead, and mercury). a. AgNO_3(aq) + FeCI_3 (aq) rightarrow AgCI(s) + Fe (NO_3)_3 (aq) c. Ag^+ (aq) + cl' (aq) rightarrow AgCl(s) d. Both b and c are right The K_c for the dissociation of SO_3 at 80 degree C is 0.0035. The chemical equation for this equilibrium dissociation is: 2SO_3(g) 2SO_2(g) + O_2(g) K_c = 0.0035 Two students were independently measuring the equilibrium positions of the components of this reaction under identical conditions. Student A reported that at equilibrium [SO_3] = 0.15 M; []SO_2] = 0.03 M and [O_2] = 0.0875. Student B chose to write the equilibrium expression as: 2SO_2(g) + O_2(g) 2SO_3(g) In student B's lab notebook we should see: a. Identical equilibrium concentrations and the same K-c b. Identical equilibrium concentrations but a larger K_c c. A larger K_c and therefore a higher concentration of oxygen. d. A larger K_c and therefore a lower concentration of oxygen.Explanation / Answer
1)option C, 500 mL of 0.18 M HCl , solute = HCl, solvent = H2O, 0.09 moles of H3O+ in 0.5 L of Solvent (H2O).
2) option A , mole fraction of benzene is more than mole fraction of toluene
( both are 150 g but molecular weight of benzene is lower than that of toluene so same mass of benzene will have more number of moles[1.92 mole] than toluene[1.63 moles])
3) option C, Ag+(aq) + Cl-(aq) --------> AgCl(s)
( 3Ag+(aq) + 3NO3-(aq) + Fe3+(aq) + 3Cl-(aq) --------> 3AgCl (s) + Fe3+(aq) + 3NO3- (aq) underlined are common for side , so remaining terms are net ionic reaction.)
4) option B, Identical concentration with larger Kc
( Kc = [product]/[reactant], for forward reaction [0.03]2[0.0875]/[0.15]2 = 0.0035, for backward reaction [0.15]2/[0.03]2[0.0875] or 1/0.0035 which larger than 0.0035 [285.7] )