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Help please? Suppose that during the NaOH standardization procedure in Part A yo

ID: 509550 • Letter: H

Question

Help please? Suppose that during the NaOH standardization procedure in Part A you misread the balance and recorded a KHP sample mass that was greater than the actual mass. How will this error influence the calculated NaOH concentration? a. Calculated concentration will be higher than the correct concentration. b. Calculated concentration will be lower than the correct concentration. c. Calculated concentration will not be influenced. Explain your answer: ________ Suppose that during the NaOH standardization procedure in Part A you spill some of the weighed KHP sample before it can be dissolved in water. You continue on with the procedure as if nothing had happened. How will this error influence the calculated NaOH concentration. a. Calculated concentration will be higher than the correct concentration. b. Calculated concentration will be lower than the correct concentration. c. Calculated concentration will not be influenced. Explain your answer: ___________ Suppose that while titrating a KHP sample in Part A you run past the end point and add more NaOH than you should. How will this error influence the calculated NaOH concentration? a. Calculated concentration will be higher than the correct concentration. b. Calculated concentration will be lower than the correct concentration. c. Calculated concentration will not be influenced. Explain your answer: ______________ Suppose that while titrating a diluted vinegar sample in Part B you suddenly realize that you forgot to add the indicator. You add the proper amount of indicator to the flask, and the contents remain colorless. What should you do? a. Continue the titration as if no mistake had been made. b. Discard the sample and start over with a fresh diluted sample. C. Complete the titration but do not use the data in your calculations. Explain your answer: ________________

Explanation / Answer

1) Answer : a

Calculated concentration will be higher than the correct concentration

Explanation : as calculation made on the basis of recorded weight of KHP which is higher than actual, while during actual titration it requires less NaOH to neutralize hence the calculated concentration will be higher than correct calculation

2) Answer : a

Calculated concentration will be higher than correct calculation

Explanation : as per recorded weight of KHP calculations made for the required NaOH concentration but in this case as actual amount of KHP sample taken for titration is less than taken for calculation and it requires less quantity of NaOH to neutralize hence calculated concentration will be higher than correct calculation.

3) Answer : b

Calculated concentration will be lower than the correct calculation

Explanation : as excess addition of NaOH to the KHP will result in dark colour and will not give actual quantity required for titration and will give NaOH required quantity more than actual so the calculated concentration will be lower than the correct calculation

4) Answer: a

Continue the titration as if no mistake had been made

Explanation : as indicator is colourless in acidic medium and turns pink on addition of base as it's pH increases and here the solution becomes colourless on addition of indicator so continue titration as if no mistake had been made