1. A student standrdized a NaOH soln. using 15.00mL of 0.250 M HCl as a primary standard. Titration required 42.73 mL of NaOH. Cal the molarity of NaOH soln.
2. A NaOH soln of unknown concentration was standardized against KHP. It took 45.78 mL of NaOH soln to completely titrate 1.256 g of KHP. Cal the molarity of NaOH.
3. Students made the following common errors while standardizing NaOH using KHP as the primary standard. How will each of these errors affect the molarity of NaOH as compared to the correct value? Will it be higher, lower, or no different? Give a reason for each answer.
a. a small amount of KHP is spilled after weighing and while transferring to flask.
b. an air bubble in the buret tip releases in the middle of the titration.
c. the student titrates to a dark pink endpoint.
d. the student adds 150.00mL of water to flask instead of 100.00mL
e the KHP is damp when the student weighs it