Mass-Mass Relationships

By knowing the mass of the sodium carbonate reactant, the mass of sodium chloride product can be calculated by using the mass-mass relationship including the use of the mole ratio between them. This experiment is carried out to prove this mass-mass relationship correct between sodium carbonate and sodium chloride

Aim: To prove the mass-mass relationships by measuring the amount of sodium chloride produced

Apparatus:                 - One 150 cm3 Beaker                - 100 cm3 Graduated Cylinder        

                        - Bunsen Burner                - Heat Proof Mat

                        - Tripod                                - Gauze

                        - Safety Goggles                        - Balance to 0.01 g

Reagents:                                 - 1.0 M HCl Solution

                                        - Solid Na2CO3

Hypothesis: I think 3.31 gram of sodium chloride will be produced.

Method:

1. Weigh the mass of a clean, dry 150 cm3 beaker to the nearest 0.01g. Then weigh out as accurately as possible, 3.0 g of Sodium Carbonate using the beaker.
2. Calculate the number of moles of HCl required in order for all the sodium carbonate to react. ;
3. Calculate the number of moles of HCl required reacting completely with the sodium chloride and then multiplying the number of moles of HCl required by 1000 to get the volume of acid required. Since the HCl contains 1.0 mole per liter.
4. Then, add 10% to the calculated amount in order for the HCl to be in excess
5. Measure out the final amount of HCl in a graduated cylinder
6. Pour the acid slowly into the beaker containing the solid sodium carbonate and record any observations
7. Heat the beaker with the Bunsen burner until   of the liquid has evaporated
8. Place the beaker in the oven to dry for 24 hours
9. Remove the beaker from the oven and determine the mass.

Results:

• Effervescence occurred when the acid reacted with the sodium carbonate

Conclusion: The mass of sodium chloride produced, 9.17g was three times the amount of the expected mass, 3.31g, giving a 63.9% percentage error.

Evaluation: This experiment could be improved by using a much more accurate weighing balance and making sure that all the water has been completely evaporated to give a pure anhydrous sodium chloride.