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Aim: To react NaHCO3 with HCl to form NaCl and two other products and then calculate the mole relationships between NaHCO3 and NaCl and calculate a balanced equation for this reaction. Safety: ???Wear safety goggles at all time ???Handle all chemicals with care ???Use equipment like tongs when handling warm/hot objects ???If chemicals are spilt on self, wash off immediately ???Stand at all times Hypothesis: The NaHCO3 will react successfully with the HCl and will form NaCl, H2O and CO2. Then be able to work out a balanced equation for the reaction and work out the moles of NaHCO3 and NaCl. Materials: ???Evaporating basin ???Watch glass Dropping pipette ???250ml beaker ???50ml beaker ???10ml measuring cylinder ???Bunsen burner ???Gauze mat ???Tripod ???Matches ???Rubber mat ???Scales ???Beaker tongs ???Tongs ???Spatula ???Distilled water bottle ???6 molar/litre HCl ???NaHCO3 Method: 1. Measured the weight of the empty evaporating basin to the nearest 0. 01grams. 2. With the spatula, added exactly 1. 5g to the evaporating basin and then wrote down the weight of the basin and the NaHCO3. 3. Measured out 6ml of the 6 molar HCl into the 10ml measuring cylinder and then transferred that into the 50ml beaker. 4. Placed watch glass over the evaporating basin and slowly added the HCl by using the pipette.
Dropped the HCl in by allowing it to enter via the lip of the evaporating basin and letting the HCl slide slowly in. 5. Continued adding the HCl to the NaHCO3 until no more reaction occurred. Double checked by swirling the basin around to see if the HCl had reached all of the NaHCO3. 6. Then removed watch glass from basin with tongs and let the liquid fall into the evaporating basin. What was left on the watch glass was rinsed with a very minimal amount of distilled water into the basin. 7. Filled the 250ml beaker with a 1/3 of water and prepared the Bunsen burner.
Then placed the evaporating basin over the beaker and placed the beaker over the Bunsen burner hence creating a water bath. Continued to heat liquid until it dried into a solid taking care not to let it over boil. 8. Once all moisture evaporated, removed basin from beaker and allowed to cool. Once cool enough to touch weighed the mass of the substance and basin to the nearest 0. 01grams. 9. After weighing mass, rinsed substance down the drain and cleaned up. Results: Mass: Basin29g Basin + NaHCO330. 50g NaHCO31. 5g Basin + NaCl30. 41g NaCl1. 41g Moles: NaHCO30. 018 NaCl0. 024 1) Moles of NaHCO3= given weight
Molecular weight =1. 5 84 =0. 017857142 approximately =0. 018 2) Moles of NaCl = given weight Molecular weight =1. 41 58. 5 = 0. 024102564 approximately = 0. 024 3) Ratio NaHCO3 : NaCl 0. 018 : 0. 24 0. 018 / 0. 018 : 0. 024 /0. 018 1 : 1. 333 1 x 3 : 1. 333x 3 3 : 4 Balanced chemical equation= NaHCO3 + HCl NaCl + H2O + CO2 Discussion: In our experiment we reacted HCl with NaHCO3 which formed NaCl, water and CO2. During the experiment noticed that adding the HCl to the NaHCO3, it fizzed with quite audible sounds and continued to do so until every particle was dissolved.
It also made the watch glass foggy due to the water vapor produced by the reaction. We know that our balanced equation is correct through the law of conservation of mass which states that matter can be neither created nor destroyed but can change forms. From our results we know that we had 1. 5g of NaHCO3 (the mass of the basin and the NaHCO3 minus the basin) and once we added the HCl to create the NaCl, the NaCl weighed to be 1. 41g. So it weighed to be 0. 09g lighter than what we started with. With the law of conservation of mass, we know that this 0. 9g was transferred into the mass of H2O gas or CO2 gas which was mixed into the air while drying the substance out over the water bath. From the balanced equation we know that for every one mole of NaHCO3 there will be one mole of NaCl. Before I knew the balanced equation I worked out the mole ratios to be 1 mole of NaHCO3 to every 1. 3333 moles of NaCl which then worked to be evenly every 3 moles of NaHCO3 to every 4 moles of NaCl. We now know that the first assumption was wrong as it was 1/3 too much and wouldn’t have worked in with the chemical equation.
The aim was to react NaHCO3 and HCl together and successfully create NaCl and two other gases which we know as H2O and CO2. We also worked out the balanced equation and the moles from this experiment and it was successfully achieved. My hypothesis was also correct. From looking at the 2 starting products and knowing one of the end products, I knew there would have to hydrogen, carbon and oxygen to have just the same elements as the starting ones had. From this I placed in 2 well known substances that had hydrogen, carbon and oxygen which happened to be H2O and CO2. I was also able to work out the moles of NaHCO3 and HCl.
One of the biggest problems we occurred was time. Our NaCl was drying over the water bath, but we had to take it off before it had time to completely dry out. This is a reason why my first assumption about the mole ratios may have been out. If the NaCl had have been over the water bath for longer, more of its end mass would have been transferred into the mass of the H2O or CO2 gas hence making the NaCl solid lighter. With the NaCl lighter, the number of moles of NaCl would have been closer to the number of moles of NaHCO3 which then would have led to a closer mole ratio then first predicted.
So if I were to do this experiment again, I’d simply allow myself more time. Another error may have been with the scales. Our readings may not have been accurate enough or the scales may have inaccurate which would then lead to the whole experiment being out. Conclusions: From the experiment know that the balanced chemical equation is NaHCO3 + HCl NaCl + H2O + CO2 Also know the number of moles in NaHCO3 is 0. 018 and the number of moles in NaCl is 0. 024.