Lab 1- Titration using a buret

Glassware and Chemicals used

• 25mL buret stand

• 125mL Erlemeyer flask ( 4 of them for the tirals)

• 5.00mL graduated cylinder or pipet

• 0.100 M NaOH solution (goes in the burret)

• Unknown HCl solution - 5mL for each trial

• 3 drops of phenolphthalein indicator

Lab Procedure

• Rinse the buret with 5mL of the 0.100 M NaOH and discard it into the beaker (put it in waste when finished)

• Fill the burret to the 0.00 mL with NaOH (meniscus bottom on the line)

• Measure out 5.00mL of acid and put into the 125mL flask

• Add 3 drops of phenolphthalein to that and swirl

• Record the initial buret reading

• Titrate the NaOH slowly while watching the volume

• Stop once you have reached a light pink color

• Record the final buret reading (volume of NaOH = Final - Initial)

• Repeat for trials 1-3

What type of chemical reaction is this?

Neutralization (Acid Base)

how do you read a buret?

top of the meniscus at eye level to bottom

How do you calculate the avarage of the 3 trials?

• Add the three trial volumes together

• Divide by the amount of trials (in this case 3)

How do you calculate the standard deviation of the 3 trials?

• Find the average of the 3 trials

• then do (volume of HaOH added - the average) make sure to do this for each trial individually

• once you find that difference square each of those values

• add those squared numbers up and the divide by 2

• take that result and square root that to get your final answer

• Formula (Volume of NaOH added for trial 1 - Average of trial 1) ² + (Volume of NaOH added for trial 2 - Average of trial 2) ² + ((Volume of NaOH added for trial 3 - Average of trial 3)² /2 square root that number

How do you find the volume of NaOH added

(final - inital)

How to find percent error

%error = experimental  - true value/ true value * 100

• in context of this expirement you would use this formula- (Avg. volume of NaOH added for the three trials- Actual volume of NaOH) / Actual volume of NaOH *100