Determine how the following scenarios will affect the calculations in Parts A, B

Question

Determine how the following scenarios will affect the calculations in Parts A, Beta and C How will the concentration of NaOH be affected if during the titration some of the solid potassium hydrogen phthalate was spilled during the transfer'^7 Will the concentration of the standardized NaOH increase, decrease or have no effect? Explain. How will the molar mass be affected if some of the solid remained after the titration was complete? Will the molar mass increase, decrease or have no effect? Explain. How will the calculated concentration of acetic acid in vinegar be affected if the liquid retained in the pipet is blown out? Will the concentration of acetic acid in vinegar increase, decrease, or have no effect? Explain. How will the calculated concentration of acetic acid in vinegar be affected if during the titration an air bubble appears in the tip of the buret and is not noticed until the endpoin is reached? Will the concentration increase, decrease or have no effect? Explain.

Explanation / Answer

a) Less moles of KHP leaves Less moles of NaOH to react to completion. (KHP=Pottasium hydrohen pthalate)
If you are under the assumption that MORE moles of KHP are in solution than there actually are, you have a false thought that the NaOH is stronger than it actually is.

You think the concentration is high, but in reality, the NaOH has less to react with.

So in answer A, the concentration will be artificially HIGH.


B) I'd need the experimental procedure

C) The concentration of acetic acid would increase. A standard pipet dispenses a set increment of liquid (10ml, 25ml ect) After the liquid has been dispensed, there is a little left in the tip.

The question is asking, if i add the liquid remaining in the tip, how will that effect the concentration of acetic acid in vinegar.

So you write that you've dispensed 10ml for example, but in reality(because you blew out the pipet) you blew out 10.05ml. In your calculations, you have 1) a lower volume of vinegar than you actually dispensed (10 instead of 10.05) and 2) an incorrect number of moles.

More moles in less volume
THE CONCENTRATION OF ACETIC ACID WOULD BE ARTIFICIALLY HIGH

d) If you are titrating a base against acetic acid, and an air bubble appears, and you dispense it, you are adding less base than the markings on the buret show. By added less, the titration will take longer, requiring more moles of base to reach the endpoint. If you think that it took more base to reach the endpoint than it actually took, you are going to assume the CONCENTRATION OF ACETIC ACID TO BE HIGHER THAN IT ACTUALLY IS

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