Question

1. Suppose 1.00 g of NaOH is used to prepare 250 mL of an NaOH solution. Compare the expected molarity of this solution to the actual average molarity you measured in the standardization. What do you notice? 2. Do you think the results would have been more accurate if a different type of acid or base were used in the standardization? Why, or why not? 3. There are many different primary standards that could be used in a standardization titration. What are the criteria for a primary standard?

Answer 1

Answer:

See explanation

Explanation:

The calculated concentration of the sodium hydroxide is;

Number of moles= mass/molar mass = 1g/40gmol-1 = 0.025 moles

Concentration= number of moles/volume= 0.025×1000/250 = 0.1 M

This calculated concentration will be different from the molarity of NaOH obtained by standardization with acid. The result will not be more accurate if a different acid is used for the standardization this is because sodium hydroxide is deliquescent and absorbs moisture thereby leading to inaccuracy in the calculated molarity.

Any substance that must be used as a primary standard must not absorb moisture, it must be stable and it must be a substance in its pure form.