BQ: 1) what is the strength of the antacid?
2) How accurate/precise is this strength?
Goggles and gloves must be worn at all time during experiment to prevent any contact with eyes and skin. If spilled any chemical in gloves throw it away and wear a new one immediately. Handle all chemical carefully. Handle all carefully to prevent from breaking. Procedure and Tests:
1) 600ml of a 0.5M NaOH solution will be needed, 3MNaOH is provided. Determine how much of the 3M NaOH will be needed. 2) Determine how many mls of a 0.5M NaOH solution will be required to titrate 1.2g of potassium hydrogen phthalate to the nolphthalein endpoint. 3) Use bromothymol blue or phenolphthalein.
1) Determine the molarity of the NaOH prepared from precedent week. 2) Estimate how many mls of NaOH solution will be required to reach the bromothymol blue endpoint. 3) Identify the antacid preparation that will be used.
1) Preparation and standardization of NaOH
1. Prepare NaOH solution by using stock 3M NaOH. Prepare 600ml of a 0.5 M NaOH. 2. Weigh a sample of potassium hydrogen (KHP) between 1.1 to 1.3 gram. 3. Dissolve the KHP by adding 50 ml of water. Swirl to complete solution. 4. Titrate be as accurate as possible, repeat titration several times. 2) Preparation and standardization of HCl.
1. Prepare hydrochloric acid stock solution.
2. Measure out a sample of HCl. Use a 10 ml volumetric pipet to transfer solution to flask and add indicator. 3. Perform titration.
3) Antacid Titration
1. Measure out the amount of sample decided
2. Add an excess of acid. Add 10.00 mL of standard HCl solution to sample. Swirl to mix. 3. Back titration.
Data, Observations and Calculations:
600mL*0.5M NaOH=M2* 3M NaOH
M2= 300mL NaOH/3 M NaOH
Data 1, standardization of NaOH
trials| KHP(g)| Moles of KHP| Moles of NaOH| .5 M...