Hey guys, I have a chem test coming up and my instructor posted a review packet with solutions. The solutions are just the answers, though, and don't show any of the work. I worked through most of it, but I'm stumped by these problems. I'm including the answers.
3. Propanoic acid (CH3CH2COOH) has a Ka of 1.34 ´ 10-5. A 25.00 mL sample of 0.1000 mol L-1 propanoic acid (in flask) is titrated with 0.1000 mol L-1 NaOH solution, added from a buret. What is the hydroxide ion concentration after 26.00 mL of NaOH are added?
Answer: 1.96 x 10-3 mol L-1
4. What is the pH of 375 mL of solution containing 0.150 mol of propenoic acid (HA) and 0.250 mol of sodium propenoate (NaA)? (Ka for propenoic acid is 5.52 x 10-5.)
Answer: 4.48
5. Fe(NO3)3 (0.00100 mol) and KSCN (0.200 mol) are added to water to make exactly 1 liter of solution. The red complex ion FeSCN2+ is produced. Calculate the concentrations of Fe3+(aq) and FeSCN2+(aq) at equilibrium, if Kf of the FeSCN2+ is 8.9 * 10^2.
Answer: [Fe3+] = 5.6 x 10-6 mol L-1, [FeSCN2+] = 0.100 mol L-1
Thanks in advance...
3. Propanoic acid (CH3CH2COOH) has a Ka of 1.34 ´ 10-5. A 25.00 mL sample of 0.1000 mol L-1 propanoic acid (in flask) is titrated with 0.1000 mol L-1 NaOH solution, added from a buret. What is the hydroxide ion concentration after 26.00 mL of NaOH are added?
Answer: 1.96 x 10-3 mol L-1
4. What is the pH of 375 mL of solution containing 0.150 mol of propenoic acid (HA) and 0.250 mol of sodium propenoate (NaA)? (Ka for propenoic acid is 5.52 x 10-5.)
Answer: 4.48
5. Fe(NO3)3 (0.00100 mol) and KSCN (0.200 mol) are added to water to make exactly 1 liter of solution. The red complex ion FeSCN2+ is produced. Calculate the concentrations of Fe3+(aq) and FeSCN2+(aq) at equilibrium, if Kf of the FeSCN2+ is 8.9 * 10^2.
Answer: [Fe3+] = 5.6 x 10-6 mol L-1, [FeSCN2+] = 0.100 mol L-1
Thanks in advance...