Monitoring chemical reactions

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Question 19

Medium

A student carries out a titration to determine the concentration of a potassium hydroxide solution using dilute nitric acid.

Complete the word equation for the neutralization reaction:

$hydroxide→………………+………………\text{nitric acid} + \text{potassium hydroxide} \rightarrow \text{\dots\dots\dots\dots\dots\dots} + \text{\dots\dots\dots\dots\dots\dots}$

[2]

Look at the student's method for their experiment:

Measure $cm325.0\text{ cm}^3$ of potassium hydroxide solution into a beaker using a measuring cylinder.
Add a few drops of phenolphthalein indicator.
Fill the burette to the $cm30.0\text{ cm}^3$ line with dilute nitric acid.
Add the acid quickly in large portions to the potassium hydroxide solution until the indicator changes color.
Repeat the experiment until consistent results are obtained.

Describe and explain one improvement the student should make to their method to get a more accurate titration result.

[2]

The student repeats the titration four times. The results are shown in the table below:

Titration number	1 (Rough)	2	3	4
Volume of acid added ( $cm3\text{cm}^3$ )	22.10	20.40	20.50	21.05

Calculate the accurate volume of nitric acid that reacted with the potassium hydroxide.

[2]

Monitoring chemical reactions

Question 19

Monitoring chemical reactions Questions

Monitoring chemical reactions

Question 19

Monitoring chemical reactions Questions