Standarization of a Sodium Hyrdoxide Solution

In summary: The purpose of the titration is to measure its amount and to use it to determine the concentration of the NaOH solution. In summary, the student missed a lab and needs help understanding how to calculate the amount of potassium hydrogen phthalate used, the amount concentration of the sodium hydroxide solution, and the average concentration of the solution. The student was given data from their partners, including the use of 0.5g of KHP and three trials with varying initial and final volumes of NaOH. The homework equations c=n/v, n=m/mm, and c1v1=c2v2 are provided, but it is unclear what the student is trying to calculate. It is suggested that the student consult their lab manual
  • #1
Erayes
1
1

Homework Statement


Hello, I missed a lab before the break because I was really sick and I need help. I was given the data from my partners for the titration lab and I don't understand how to calculate the amount of potassium hydrogen phthalate used in each trial, amount concentration of the sodium hydroxide solution and the average concentration of the solution. Thanks in advance.
They used .5g of KHP.

Trials(mL)
1 2 3
Initial volume of NaOH: 0 | 5.8 | 12.2 |

Final volume of NaOH: 5.8 | 12.2 | 17.3 |
Total Volume: 5.8 | 6.4 | 5.1 |

Homework Equations


c=n/v, n=m/mm c1v1=c2v2

The Attempt at a Solution


When they say amount do they mean g or moles?
n=m/mm
n=.5/204.22
n=0.002448
Do I use the final volumes to calculate amount concentration?
 
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  • #2
Erayes said:

Homework Statement


Hello, I missed a lab before the break because I was really sick and I need help. I was given the data from my partners for the titration lab and I don't understand how to calculate the amount of potassium hydrogen phthalate used in each trial, amount concentration of the sodium hydroxide solution and the average concentration of the solution. Thanks in advance.
They used .5g of KHP.

Trials(mL)
1 2 3
Initial volume of NaOH: 0 | 5.8 | 12.2 |

Final volume of NaOH: 5.8 | 12.2 | 17.3 |
Total Volume: 5.8 | 6.4 | 5.1 |

Homework Equations


c=n/v, n=m/mm c1v1=c2v2

The Attempt at a Solution


When they say amount do they mean g or moles?
n=m/mm
n=.5/204.22
n=0.002448
Do I use the final volumes to calculate amount concentration?

Nobody can answer that nor should try because it is far too vague and unclear.
"They used 0.5 g of KHP". To do what?
OK it looks like like they used 3 volumes of the NaOH solution to titrate each time the same unstated volume of a KHP solution that was made up in unstated way from 0.5 g. KHP.
That's what you use KHP for, because you can do it precisely ("primary standard") as your book or manual certainly explains (though that precision is rather wasted given your colleagues' poor reproducibility!)
From the titrations you can deduce, within the said loose limits of their precision, the molarity of the NaOH.
That is very likely the object lf the experiment so you are asking the wrong question to the wrong people - your colleagues should tell you what they did with the KHP.
 
  • #3
Erayes said:
I don't understand how to calculate the amount of potassium hydrogen phthalate used

It is not something you should calculate - it is something that should be measured (and precisely!) before the titration. As epenguin signaled, KHP is one of these substances that can be prepared very pure and weighed very accurately.
 

What is the purpose of standardizing a Sodium Hydroxide Solution?

The purpose of standardizing a Sodium Hydroxide Solution is to accurately determine the concentration of the solution. This is important because the concentration of a solution can change over time due to factors such as exposure to air and temperature, which can affect its effectiveness in experiments or other applications.

How is a Sodium Hydroxide Solution standardized?

To standardize a Sodium Hydroxide Solution, a known amount of the solution is reacted with a known amount of a standard acid solution. The reaction is then titrated until the endpoint is reached, which can be determined by using an indicator or a pH meter. The volume of acid used in the titration can then be used to calculate the concentration of the Sodium Hydroxide Solution.

Why is it important to use a standard acid in the standardization process?

Using a standard acid in the standardization process ensures that the reaction between the Sodium Hydroxide Solution and the acid is accurately and precisely measured. This allows for a more accurate determination of the concentration of the Sodium Hydroxide Solution.

What factors can affect the accuracy of the standardization process?

The accuracy of the standardization process can be affected by factors such as human error, impurities in the Sodium Hydroxide Solution, and variations in the standard acid used. It is important to follow proper procedure and use high-quality chemicals to minimize these potential sources of error.

How often should a Sodium Hydroxide Solution be standardized?

A Sodium Hydroxide Solution should be standardized whenever it is used for a new experiment or application. It is also recommended to standardize the solution periodically, especially if it is being stored for extended periods of time, to ensure its concentration has not changed.

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