Circle the correct answer for each question 1. In which reaction does the oxidation number of oxygen increase? a. Ba(NO3)2(aq)+KSO4(aq) BaSO4(s)+2KNO3(aq b. HCl(aq)+NaOH(aq) NaCl(aq)+HO(l) c. MgO(s)+HO(l) Mg(OH) (s) d. 250(g) + O(g) 2503(g) e. 2HO(l) 2H(g)+O(g) 2. Which of the following is an oxidation-reduction reaction? a. Cu(s)+2AgNO3(aq) -2Ag(s)+Cu(NO3)2(aq) b. HCl(aq)+NaOH(aq) HO(l)+NaCl(aq) c. AgNO3(aq)+HCl(aq) AgCl(s)+HNO3(aq) - d. Ba(CHO)(aq)+NaSO4(aq) BaSO4(s)+2NaCHO(aq) e. HCO3(aq) + Ca(NO3)2(aq) 2HNO3(aq)+CaCO3(s) 3. A closed-end manometer was attached to a vessel containing argon. The difference in the mercury levels in the two arms of the manometer was 12.2 cm. Atmospheric pressure was 783 mm Hg. The pressure of the argon in the container was mm Hg. a. 122 b. 661 c. 771 d. 795 e. 882 4. The concentration of iodide ions in a 0.193 M solution of barium iodide is a. 0.193 M b. 0.386 M C. 0.0965 M d. 0.579 M e. 0.0643 M 5. Standard temperature and pressure (STP), in the context of gases, refers to a. 298.15 K and 1 atm b. 273.15 K and 1 atm c. 298.15 K and 1 torr d. 273.15 K and 1 pascal e. 273.15 K and 1 torr