How can you measure density of NaCl with a pycnometer? Please give clear steps.

Question

How can you measure density of NaCl with a pycnometer? Please give clear steps.
I know that you have to measure water volume first at certain temperature and that volume is the same as the pycnometer's which allows you then to calculate the density of NaCl. But I don't know how you can do that experimentally. Do you add NaCal to water and measure that or you add NaCl to an empty pycnometer and measure it? And why would you use a water bath? How can you measure density of NaCl with a pycnometer? Please give clear steps.
I know that you have to measure water volume first at certain temperature and that volume is the same as the pycnometer's which allows you then to calculate the density of NaCl. But I don't know how you can do that experimentally. Do you add NaCal to water and measure that or you add NaCl to an empty pycnometer and measure it? And why would you use a water bath? Please give clear steps.
I know that you have to measure water volume first at certain temperature and that volume is the same as the pycnometer's which allows you then to calculate the density of NaCl. But I don't know how you can do that experimentally. Do you add NaCal to water and measure that or you add NaCl to an empty pycnometer and measure it? And why would you use a water bath?

Explanation / Answer

Pycnometer device used to determine the relative density of a liquid. That is ratio of density of particular substance with that of water. If the flask is weighed empty, full of water, and full of a liquid whose relative density is desired, the relative density of the liquid can easily be calculated Pycnometer device enables a liquid's density to be measured accurately by reference to an appropriate working fluid, such as water or mercury, using an analytical balance.

To determine the volume of the pycnometer weigh the dry pycnometer and capillary on the analytical balance twice and use the average value. Then weigh (twice) the pycnometer and capillary filled with water after it has equilibrated in the constant temperature bath for minutes

Calculate the volume of the pycnometer from the weight of water and the known density of water. pycnometer has a number. Each capillary has a number. If you use two pycnometers, you must calibrate each one Remember to keep the capillary and vial together. The weights and volumes of the pycnometers are not identical depending on the precision of your measurements. Use this value in your calculations.

Then prepare solutions of NaCl in water of certain concentrations. Prepare these by weight in a snap top jar using an analytical balance,close to 60 g of water and an appropriate weight of salt. The molality is determined from the weights of water and salt. Begin with the most concentrated solution and finish with the least concentrated solution. Rinse the pycnometer with small amounts of each new solution. Both the preceding solution and distilled water are contaminants in this experiment. Fill the pycnometer and equilibrate at 25.0 oC with solutions that are initially at a temperature below 25.0 oC. Dry the outside of the pycnometer and weigh using analytical balance. Calculate the density of each solution.

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