It is possible to predict the mass of different products in a reaction by know the mass of the whole system (the reactants). This is due to the law of conservation being that matter cannot be created nor destroyed during chemical reaction (study, 2016).
Flask containing Hydrochloric acid
Average = 77.469 ? 0.001
Average = 18.719 ? 0.001
Average = 0.929 ? 0.001
Watch glass and sodium carbonate residue
Average = 18.720 ? 0.001
Flask and contents after reaction
Average = 78.014 ? 0.001
? Observation of the reaction:
Immediately as the sodium carbonate was added to the hydrochloric acid, it started buddling and fizzing up to the nozzle of the flask, threatening to spill out. A peculiar smelling gas was created (CO? presumably) and precipitation was started to form on the inside of the flask as the bubbling went down. During the reaction the liquid went from clear to milky white and when it was finished back to transparent.
? Establish the exact mass of sodium carbonate that reacted.
The weight of the watch glass without residue and with residue differed by 0.001 g ? 0.001, the weight without being 18.719 g ? 0.001 and with being 18.720 g ? 0.001. This means that the exact mass of sodium carbonate reacting would be the original mass, 0.929 g minus the 0.001 of residue left on the watch glass:
Some sodium carbonate, although the exact amount is unknown, was lost during the process of transferring the content to the flask. This will be explored further in errors.
? Write a balanced equation for the reaction of sodium carbonate and hydrochloric acid.
2HCl + Na?CO? -> 2NaCl + CO? + H?O
? Determine the moles of sodium carbonate reacted.
? Determine the theoretical number of moles of carbon dioxide produced.
In theory: 1 mole of Na?CO? = 1 mole of CO?
Therefore: 0.00875 moles ? 0.00001 of Na?CO? = 0.00875 moles ? 0.00001 of CO?
This amount should have been produced during the reaction.
? What mass of carbon dioxide does this represent?
? How does this theoretical yield compare with the actual yield?
Theoretical yield of CO? = 0.385g ? 0.00044
Actual yield of CO? = (weight of flask & hydrochloric acid before reaction + weight of sodium carbonate before reaction) ? weight of flask and contents after reaction
The %error between the theoretical CO? yield and the actual yield is approximately 0.2% ? 0.9
? Account for any difference by reflecting on the accuracy of measurements and technique and considering the chemistry of the reaction products.
This experiment proved to be very accurate as the percentage error between the theoretical...