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March 27, 2017

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What improvements could i make to this lab? so far i only have that the graduated cylinder should be changed to a buret for a more accurate measurement.

Procedure:
Part 1
Begin by measuring the mass of the empty calorimeter and record the value. Next, add approximately 1-1.5 g of solid NaOH pellets and record the mass. Carefully grind up the pellets using a mortar and pestle. Then, transfer the ground up NaOH into the calorimeter and measure the mass. Pour 25 mL of 6 M HCl into a graduated cylinder. Measure the temperature of the HCl prior to the reaction using a thermometer. Then, transfer the liquid HCl from the cylinder to the calorimeter containing the ground up NaOH and replace the lid and thermometer. Observe the rising temperature and record the temp of the reaction. Measure the combined mass of all the contents in the calorimeter and record the value.

Part 2
Secure the stand and two clean burets. Using the funnel, fill one buret to the 0 mark with HCl. Rinse out the funnel thoroughly and carefully fill the other buret to the 0 mark with 2 M NaOH solution. Drain 25 mL of NaOH solution into the calorimeter. Record the mass of the calorimeter with the NaOH. Next, take the temperature of the NaOH and record the value. Add 25 mL of HCl, quickly, to the calorimeter. Observe the temperature and record the final temperature of the contents. Take the final mass of the contents.

  • Chemistry - ,

    Begin by measuring the mass of the empty calorimeter and record the value. Next, add approximately 1-1.5 g of solid NaOH pellets and record the mass. Carefully grind up the pellets using a mortar and pestle. Then, transfer the ground up NaOH into the calorimeter and measure the mass. Pour 25 mL of 6 M HCl into a graduated cylinder. Measure the temperature of the HCl prior to the reaction using a thermometer. Then, transfer the liquid HCl from the cylinder to the calorimeter containing the ground up NaOH and replace the lid and thermometer. Observe the rising temperature and record the temp of the reaction. Measure the combined mass of all the contents in the calorimeter and record the value.

  • Chemistry - ,

    Part 2
    Secure the stand and two clean burets. Using the funnel, fill one buret to the 0 mark with HCl. Rinse out the funnel thoroughly and carefully fill the other buret to the 0 mark with 2 M NaOH solution. Drain 25 mL of NaOH solution into the calorimeter. Record the mass of the calorimeter with the NaOH. Next, take the temperature of the NaOH and record the value. Add 25 mL of HCl, quickly, to the calorimeter. Observe the temperature and record the final temperature of the contents. Take the final mass of the contents.

    sorry, it would only let me post in segments

  • Chemistry - ,

    I'm not sure what you are to calculate; perhaps it is delta H/mol or gram. Also, you don't specify the kind of calorimeter you are using. You might be using a styrofoam cup one or a real calorimeter.
    How did you weigh the material(s)? Would a better balance have helped?
    Did you dry the NaOH before grinding it. Most NaOH purchased contains an impurity of Na2CO3 (from CO2 absorption from the air). Grinding it allows it to absorb more CO2 as well as absorb moisture from the air. So using pure NaOH, if that can be obtained, and grinding/weighing in an inert atmosphere might improve that part of the procedure. Most labs that need good NaOH prepare a solution of NaOH, then standardize it with a primary standard. I hope this helps a little.

  • Chemistry - ,

    Thanks, yes i used a styrofoam calorimeter. the objective of the lab was to calculate the heat of formation of both solid and aq NaOH

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