Reaction Stoichiometry

Summary

In this experiment, the reaction between hydrochloric acid (HCl) and sodium bicarbonate (NaHCO3) is explored to observe the production of carbon dioxide gas and the formation of sodium chloride (salt). The process involves measuring the mass changes before and after the reaction with varying amounts of sodium bicarbonate (1g, 1.5g, 2g). The gas released during the reaction causes a decrease in the system's weight. After the reaction, sodium chloride is recovered through evaporation. The results show varying amounts of salt produced, allowing the calculation of the percentage yield from the reactants.

Takeaways

• 😀 The experiment investigates the relationship between moles in a balanced chemical equation using hydrochloric acid (HCl) and sodium bicarbonate (NaHCO3) as reactants.
• 😀 Three different masses of sodium bicarbonate are used: 1g, 1.5g, and 2g, each with 20 mL of 1.5 molar hydrochloric acid.
• 😀 The sodium bicarbonate is placed in separate beakers, and hydrochloric acid is added to each before being weighed on a balance.
• 😀 When hydrochloric acid and sodium bicarbonate react, carbon dioxide gas is released, which is observed as gas bubbles forming in the solution.
• 😀 The mass of the reaction mixture decreases as carbon dioxide escapes, with the final mass recorded after the reaction.
• 😀 The masses after the reactions are: 77.9g (1g NaHCO3), 79.1g (1.5g NaHCO3), and 79.7g (2g NaHCO3).
• 😀 After the reaction, the remaining product is a mixture of sodium chloride (NaCl) and water, forming an aqueous sodium chloride solution.
• 😀 The aqueous solution of sodium chloride is heated to evaporate the water, leaving behind solid sodium chloride.
• 😀 After evaporation, the mass of sodium chloride is measured, and the yield is calculated for each reaction.
• 😀 The final mass of sodium chloride recovered is 0.7g for 1g NaHCO3, 1.0g for 1.5g NaHCO3, and 1.5g for 2g NaHCO3.

Q & A

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

The main objective of the experiment is to verify the mole relationship in a balanced chemical equation by reacting hydrochloric acid (HCl) with sodium bicarbonate (NaHCO₃) and determining the percentage yield of the product sodium chloride (NaCl).

Which reactants are used in the experiment?

The reactants used are hydrochloric acid (HCl) and sodium bicarbonate (NaHCO₃).

What are the different masses of sodium bicarbonate used in the experiment?

The experiment uses three different masses of sodium bicarbonate: 1.0 gram, 1.5 grams, and 2.0 grams.

How much hydrochloric acid is used in each reaction setup?

Each reaction setup uses 20 milliliters of 1.5 molar hydrochloric acid (HCl).

What gas is produced during the reaction between hydrochloric acid and sodium bicarbonate?

The gas produced is carbon dioxide (CO₂), which is observed as bubbles during the reaction.

Why does the mass of the system decrease after the reaction?

The mass decreases because carbon dioxide gas is released and escapes from the reaction mixture, reducing the total mass measured on the balance.

What are the products formed in the reaction between hydrochloric acid and sodium bicarbonate?

The products are sodium chloride (NaCl), carbon dioxide (CO₂), and water (H₂O).

What process is used to recover sodium chloride from the solution after the reaction?

The evaporation process is used to remove water, leaving behind solid sodium chloride in the evaporating dish.

What were the observed actual yields of sodium chloride for the three trials?

The actual yields were approximately 0.7 grams of NaCl for 1.0 gram of NaHCO₃, 1.0 gram of NaCl for 1.5 grams of NaHCO₃, and 1.5 grams of NaCl for 2.0 grams of NaHCO₃.

What is the significance of determining the percentage yield in this experiment?

Determining the percentage yield allows comparison between the theoretical and actual amounts of sodium chloride produced, helping to evaluate the efficiency of the reaction and the accuracy of the experimental procedure.

What observation indicates that the evaporation process is complete?

The evaporation process is complete when the solution becomes completely dry and white solid residues of sodium chloride are visible along the sides of the evaporating dish.

What is the balanced chemical equation for the reaction performed?

The balanced equation is NaHCO₃ + HCl → NaCl + H₂O + CO₂.