SOLVED

21) The titration of 25.0 mL of an unknown concentration H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution (in M)? A) 0.20 M B) 0.40 M C) 0.10 M D) 0.36 M E) 0.25 M 22) The titration of 80.0 mL of an unknown concentration H3PO4 solution requires 126 mL of 0.218 M KOH solution. What is the concentration of the H3PO4 solution (in M)? A) 1.03 M B) 0.343 M C) 0.114 M D) 0.138 M E) 0.0461 M 23) Determine the oxidation state of P in PO33-. A) +3 B) +6 C) +2 D) 0 E) -3 24) Determine the oxidation state of C in CO3-2. A) +4 B) +2 C) -2 D) -4 E) +6 25) Determine the oxidation state of nitrogen in NO. A) +5 B) +3 C) 0 D) +2 E) +4 26) Determine the oxidation state of nitrogen in NO2. A) +5 B) +3 C) 0 D) +2 E) +4 27) What element is undergoing oxidation (if any) in the following reaction? CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) A) O B) H C) C D) both C and H E) None of the elements is undergoing oxidation. 28) What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) → Zn(NO3)2(aq) + 2 Ag(s) A) Zn B) N C) O D) Ag E) This is not an oxidation-reduction reaction. 29) What element is undergoing oxidation (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) → Zn(NO3)2(aq) + 2 Ag(s) A) Zn B) N C) O D) Ag E) This is not an oxidation-reduction reaction. 30) Determine the reducing agent in the following reaction. 2 Li(s) + Fe(C2H3O2)2(aq) → 2 LiC2H3O2(aq) + Fe(s) A) O B) H C) C D) Fe E) Li