Percent Yield for Synthesis of NaCl from Reaction of Sodium Bicarbonate and Hydrochloric Acid

Summary

In this experiment, PJ Pepin demonstrates the reaction between sodium bicarbonate and hydrochloric acid, producing sodium chloride (NaCl), water (H₂O), and carbon dioxide (CO₂). The process involves weighing the reactants, mixing them to initiate the reaction, and then evaporating the solution to isolate solid NaCl. After obtaining the actual yield of NaCl, the theoretical yield is calculated based on stoichiometric principles. The experiment shows an almost perfect 100% yield, confirming the accuracy of the calculations and the completion of the reaction.

Takeaways

• 😀 The experiment involves mixing sodium bicarbonate (baking soda) with hydrochloric acid to produce water, carbon dioxide, and sodium chloride (NaCl).
• 😀 The initial mass of the empty beaker was recorded before adding the sodium bicarbonate.
• 😀 Sodium bicarbonate was added to the beaker, and its mass was weighed again after addition.
• 😀 Hydrochloric acid (31% concentration) was added to the sodium bicarbonate, causing a reaction that produced bubbles (carbon dioxide).
• 😀 The reaction was observed to stop bubbling, indicating that the reaction had completed.
• 😀 Water was added to dissolve excess sodium chloride (NaCl), which was initially difficult to dissolve due to the high chloride ion concentration.
• 😀 The mixture was heated on a hot plate to evaporate water and excess hydrochloric acid, leaving behind solid sodium chloride.
• 😀 After evaporation, the mass of the remaining solid sodium chloride was measured and found to be 2.08 grams.
• 😀 The theoretical yield of sodium chloride was calculated by converting the mass of sodium bicarbonate into moles and using stoichiometric ratios.
• 😀 The theoretical yield of sodium chloride was calculated to be 2.07 grams, which was very close to the actual yield (2.08 grams), indicating a high accuracy.
• 😀 The experiment demonstrated that the actual yield was very close to the theoretical yield, suggesting nearly a 100% yield in the reaction.

Q & A

What is the main objective of the experiment described in the transcript?

The main objective is to perform a reaction between sodium bicarbonate (baking soda) and hydrochloric acid to produce water, carbon dioxide, and sodium chloride, and to determine the actual and percent yield of the sodium chloride formed.

Which chemical reaction is being demonstrated in the experiment?

The reaction demonstrated is an acid-base reaction: NaHCO₃ (sodium bicarbonate) reacts with HCl (hydrochloric acid) to form NaCl (sodium chloride), CO₂ (carbon dioxide), and H₂O (water).

How was the sodium bicarbonate prepared and measured before the reaction?

The empty beaker was first weighed, then sodium bicarbonate was added and weighed again to determine the mass used in the reaction, which was 2.98 grams.

What visual indication shows that the reaction between sodium bicarbonate and hydrochloric acid is occurring?

Bubbling is observed during the reaction, which indicates the release of carbon dioxide gas as the reaction proceeds.

Why was some water added to the mixture during the experiment?

Water was added to help dissolve any sodium chloride that did not initially dissolve due to the high concentration of chloride ions in the solution.

How was the sodium chloride product isolated from the reaction mixture?

The reaction mixture was heated on a hot plate to evaporate the water and any excess hydrochloric acid, leaving behind solid sodium chloride in the beaker.

What was the actual yield of sodium chloride obtained from the experiment?

The actual yield of sodium chloride obtained was 2.08 grams.

How was the theoretical yield of sodium chloride calculated?

Theoretical yield was calculated by converting the mass of sodium bicarbonate (2.98 g) to moles, using the 1:1 molar ratio with sodium chloride, and then converting the moles of sodium chloride to grams, giving a theoretical yield of 2.07 grams.

What is the percent yield of the reaction, and how is it determined?

The percent yield is approximately 100%, calculated by dividing the actual yield (2.08 g) by the theoretical yield (2.07 g) and multiplying by 100%.

What factors could contribute to slight discrepancies between the actual and theoretical yield?

Discrepancies could be caused by incomplete drying of sodium chloride, minor measurement errors, or loss of product during transfer and handling.

Why is it important to observe the reaction until bubbling stops?

Observing until bubbling stops ensures that the reaction is complete and all sodium bicarbonate has reacted with hydrochloric acid, preventing underestimation of the yield.

What does the reaction demonstrate about the solubility of sodium chloride in concentrated chloride solutions?

The experiment shows that sodium chloride has limited solubility in solutions with a high concentration of chloride ions, which is why additional water was needed to dissolve it completely.