• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Determination of % Yeild

Extracts from this document...


Renee Buettel Period D4 Ms. Parziale 1/31/08 Lab #11: Determination of % Yeild Paul Bergin Abstract The main objective of this experiment was to find the mole to mole ratio of is NaHCO3(s), or sodium bicarbonate, to NaCl, or sodium chloride when it is reacted with excess hydrochloric acid. The result of this was a 1 to 1 ratioThe other main objective, which was similar to the first, was to find the mole ratio of sodium carbonate to sodium chloride reacted with excess HCl. The result of this was a 1 to 2 ratio. The main theory proven in this lab experiment was the topic of percent yield. Introduction Stoichiometry is an important topic when dealing with chemistry. It is a very mathematical part of chemistry. It's used to calculate moles, percents, and masses of reactants and products in a chemical equation, according to Park (1996). A common stoichiometry problem gives an amount of a reactant and asks how much of the product will be formed. The same source explains that in a mass-to-mass problem, the first step is balancing the equation. Next, the mass is converted to moles using the molar mass of the given substance in the formula n=m/GFM. A mole ratio is then used to convert the moles of the known to the moles of the unknown. Finally, the moles are converted to mass using the formula n=m/GFM. ...read more.


Then using your dropper pipette, add the HCl drop by drop to the sodium bicarbonate in the evaporating dish. The reaction will be evident by the bubbling that takes place. Gently mix the reactants after every 3-4 drops of HCl. Continue adding HCl until the bubbling stops and all of the NaHCO3 is dissolved - this indicates that the reaction is complete. 4. Assemble the stand, ring clamp and wire gauze apparatus for heating as shown in the figure below. Cover the evaporating dish with the watch glass and place it on the wire gauze. 5. Gently heat the solution in the covered evaporating dish with a Bunsen burner flame in order to remove the water generated in the reaction (as well as any excess HCl present). The flame should be adjusted to a lower temperature and wafted under the evaporating dish constantly. Continue heating until the contents are completely dry. Note that the watch glass cover should also be dry! 6. After allowing the evaporating dish to cool to room temperature, measure and record the mass of the evaporating dish + watch glass + residue (NaCl). 7. Repeat steps 1 to 6 with a 0.3 - 0.4 g sample of sodium carbonate (Na2CO3). Results Calculations: Appendix A Table #1: Experimental and Theoretical Mass and Moles Produced from NaHCO3 Mass of NaHCO3 reactant Moles of NaHCO3 reactant Theoretical Moles of NaCl that should have been produced (ratio) ...read more.


Finally, the moles were converted to mass using the formula n=m/GFM. Percent yield was found by using the equation %yield=(actual mass of product/predicted mass of product) x 100. The hypothesis was correct. The mole ratio of each reactant to the product of NaCl in the first reaction was be to 1 to 1 due to the fact that the balanced equation was NaHCO3(s) + HCl(aq) --> CO2 + H2O(l) + NaCl(s). For the second reaction, the mole ratio of was be 1 to 2 because the balanced equation was Na2CO3(s) + 2HCl(aq) --> CO2 + H2O(l) + 2NaCl(s). All objectives were met. The main objectives, which were to find the mole ratios of sodium carbonate and sodium bicarbonate when reacted with excess hydrochloric acid, were accomplished. The percent yield equation was successfully used, which was a minor objective. Evidence of this is in Table #1. The second minor objective, which was to find the actual mass and moles of NaCl produced, was also met. There is also evidence of this in Table #1. In conclusion, this lab experiment was successful. Results Coefficients in Chemistry? (2008). Retrieved January 29th, 2008, from http://au.answers.yahoo.com/answers2/frontend.php/question?qid=20080116233108AAITP3g Chemistry Formulas (2005). Retrieved January 29th, 2008, from http://chemistryformulas.com/ How can I balance an equation? (n.d.). Retrieved January 29th, 2008, from http://misterguch.brinkster.net/eqnbalance.html J. L. Park (1996). ChemTeam: Stoichiometry: What is it?Retrieved February 9th, 2008, from http://misterguch.brinkster.net/eqnbalance.html Law Of Conservati0on of Mass Definition (n.d.). Retrieved February 9th, 2008, from http://chemistry.about.com/library/glossary/bldef5660.htm W. Volland (2005). Percent Yield for Chemical Equations. Retrieved February 9th, 2008, http://www.800mainstreet.com/6/0006-007-percent-yield.html ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Physical Chemistry essays

  1. Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

    3.26 53.67 2.76 12.53 310.50 3.22 44.00 3.37 12.73 314.17 3.18 30.67 4.83 13.09 322.67 3.10 (Table 3.7.2) A graph of ln k against (graph 3.7.2) is plotted on page 44. The graph is a straight line, as expected, and the spreadsheet gives the equation of the graph as: (Equation 3.7.2)

  2. The Determination of rate equation

    (Graph adapted from Cambridge Chemistry 2- A2) 2. from the shape of concentration-time graph: By plotting a graph of concentration-time and looking at the shape of the graph to determine the order of reaction with respect to the reagent. Zero order = If the graph obtained is a straight line

  1. Investigating how concentration affects rate of reaction

    However, I realised that this would most likely not share the same value as the temperature of the solutions in the boiling tubes. To overcome this problem I placed a thermometer in each boiling tube - one in the tube containing potassium bromide and one in the solution of the other reactants.

  2. detremining the rate equation

    I will also use the same tile with the same size cross on it. Because if the crosses were in deferent sizes this could affect when to determine the end of the reaction. Justification for the volumes and concentrations used.

  1. the determination of a rate equation

    will need to be controlled by the person, and to be kept the same throughout the experiment in order to keep it fair and get as accurate results as possible. Only the independent variable is changed. Variables: > Independent variable: concentrations of hydrochloric acid and sodium thiosulphate > Dependent variable:

  2. Which is the correct equation?

    * Wash hands when finished. Apparatus and Chemicals Method 1. Assemble the apparatus (refer to Figure 1) without the addition of potassium nitrate and check for faults and/or leaks. A quick and simple way to check if the syringe is faulty is to draw a convenient volume of air into the syringe, e.g.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work