(Solved): please answer the pre lab questions The reaction between sodium carbonate and hydrochloric acid proc ...

The reaction between sodium carbonate and hydrochloric acid proceeds according to the following chemical equation; \[ \mathrm{Na}_{2} \mathrm{CO}_{3}(\mathrm{~s})+2 \mathrm{HCl}(\mathrm{aq}) \quad 2 \mathrm{NaCl}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{~g}) \] Three products are obtained from the above reaction - carbon dioxide gas, liquid water and sodium chloride salt. Both the \( \mathrm{CO}_{4} \) gas and the liquid \( \mathrm{H}_{2} \mathrm{O} \) can be removed by heating the product miature. The residue left behind is the \( \mathrm{NaCl} \) salt. The stoichiometric relationship between \( \mathrm{Na}_{2} \mathrm{CO}_{1} \) and \( \mathrm{NaCl} \) can be quantified by measuring the mass of \( \mathrm{NaCl} \) produced from the known mass of the limiting reagent, \( \mathrm{Na}_{2} \mathrm{CO}_{3} \) In this experiment, a sample of sodium carbonate is treated with dilute hydrochlonic acid to initiate the reaction. To ensure that sodium carbonate is the limiting reactant, an indicator is used to verify that the final solution is acidic (i.e., \( \mathrm{HCl} \) is in excess). The solution is then heated to remove the excess hydrochloric acid, carbon dioxide gas and the water, leaving only the dry \( \mathrm{NaCl} \) residas. The quantity of sodium chloride produced will be determined and compared to the theoretically expected value obtained by calculation. Objective Stoichiometry refers to the proportions by mass in which various substances react. In this experiment, the stoichiometry of a reaction between sodium carbonate and hydrochloric acid is examined. "Every student in the team will conduct their own experiment 1. Wash the evaporating dish with soap and water. Rinse with distilled water and dry it. 2. Heat the evaporating dish on high heat on a hot plate for about 5 minutes to remove any trace of moisture. Allow the evaporating dish to cool to room temperature. 3. On the same hot plate, heat a \( 400 \mathrm{~mL} \) beaker filled with \( 250 \mathrm{~mL} \) of water. This will serve as the heating medium, a.k. a. hot bath. 4. Weigh the cool dry evaporating dish and record its mass. Use crucible tongs to avoid transferring moisture from your gloves to the dish. 5. Add about \( 0.3 \mathrm{~g} \) of sodium carbonate, to the evaporating dish and reweigh. Record this valoe. 6. Moisten the \( \mathrm{Na}_{3} \mathrm{CO}_{\text {3 }} \) with a small amount of distilled water (5-7 drops) and add 4 drops of methyl red indicator. The solution will turn yellow. Cover the evaporating dish with a watch glass. 7. Obtain about \( 5 \mathrm{~mL} \) of \( 3.0 \mathrm{M} \mathrm{HCl} \) in a graduated cylinder. 8. Add the \( 3.0 \mathrm{M} \mathrm{HC1} \) dropwise down the spout of the evaporating dish using a medicine dropper or a pasteur pipette without removing the watch glass until the solution is faint pink: 9. Place the evaporating dish on the hot bath to heat the solution. As the solution is heated, it may turn yellow again; if this occurs, add some more \( H C 1 \) until the indicator turns pink again. 10. Heat the reaction for \( 10 \mathrm{~min} \). 11. Remove the watch glass. Rinse any solid that may have collected on the bottom of the watch glass into the evaporating dish with a SMAL.L amount of distilled water. Do not use an excessive amount of water as ultimately it will have to be boiled off. 12. Continue heating the solution gently. As the solution becomes more concentrated, it will tend to "bump" and splatter if the heating rate is excessive, resulting in a loss ef product. 13. When the residual solid is almost dry, lower the heat of the hot plate to a minimum, remove the evaporating dish from the steam bath, dry the bottom of the dish and place it directly on the hot plate. Begin heating the evaporating dish directly with a very low heat. 14. If the contents of the evaporating dish begin to spatter return the evaporating dish to the hot bath for additional slow heating. If no spattering occurs, continue heating the evaporating dish directly with low heat for a few more minutes. 15. Remove the evaporating dish from the hot plate and allow to cool to toom temperature. 16. Weigh the cool evaporating dish and its contents. Record value. 17. Reheat and reweigh until a constant mass is obtained. re-Lab Assignment 1. If \( 10.0 \mathrm{~g} \mathrm{Na} \mathrm{CO}_{f} \) (s) are treated with excess \( \mathrm{HCl} \), calculate the theoretical yield of \( \mathrm{NaCl} \). Explain your answer.