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Reaction Stoichiometry

Name: Yara Sayegh

Subject: Chemistry

Submitted to: Ms. Lady Maalouf

Date: May 11, 2011

Class: IB-1

*Purpose:

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The purpose of this experiment was to determine the mass of calcium carbonate obtained

from the reaction between calcium chloride and sodium carbonate.

*Apparatus/Equipment/Materials:

- 3 beakers (250 mL)

- 2 spatulas

- balance ( 0.1)

- filtration setup

- 1 funnel

- ring stand

- filter paper

- stirring rod

- sodium carbonate

- calcium chloride

- distilled water

*Procedure:

1. 4.0 g of calcium chloride (111 g/mol) were weighed out and dissolved in 100 mL ofdistilled water.

2. 6.0 g of sodium carbonate (106 g/mol) were weighed out and dissolved in 100 mL ofdistilled water.

3. The sodium carbonate solution was poured into the beaker containing the calciumchloride solution.

4. The mixture was stirred. Then the filtration apparatus was set up. The filter paperwas weighed and then the mixture was filtered. The beaker was rinsed and the

contents in the funnel were emptied. After the precipitate was washed with distilled

water several times.

5. The filter paper with the precipitate was placed aside. It was left for the next labsession.

6. Lastly, the dry filter paper with the precipitate was weighed.

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*Data Collection:

Table 1: Data Collection (Mass, Volume, Appearance, etc)

CaCl2 Na2CO3 Filter Paper

Mass ( 0.1 g) 4.0 g 6.0 g 2.2 g

Amount of Distilled

Water Dissolved in(Volume of Solution) 100 mL 100 mL - - - - - - - - - - - - - - - -

Limiting or Excess

ReagentLimiting Reagent Excess Reagent - - - - - - - - - - - - - - - -

Mass of Filter Paper+ Precipitate

(CaCO3) (after

filtration) ( 0.1 g)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4.8 g

Appearance Before

Dissolved in Distilled

Water

Powdery White Powdery White - - - - - - - - - - - - - - - -

Appearance AfterDissolved in Distilled

Water

Foggy andWhitish/Particles

Visible ClearSolution

Foggy andWhitish/Particles

Visible ClearSolution

- - - - - - - - - - - - - - - -

When Na2CO3 solution was added to CaCl2 solution a very white/milky solution was

formed while filtering the solution a white residue/precipitate (CaCO3) was observedremaining in the filter paper

Figure 1: Filtration Process

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*Data Processing/Data Analysis:

Mass of Precipitate (CaCO3) Formed after Filtering the Na2CO3 CaCl2 Solution= Mass of Filter Paper and Precipitate Mass of Filter Paper

= 4.8 g 2.2 g = 2.6 g ( 0.1 g) of precipitate (CaCO3) were formed.

Calculating the Limiting & Excess Reagents? g CaCl2 = 6.0 g Na2CO3

= 6.28 g CaCl2 are required to react with 6.0 g Na2CO3

CaCl2 is the limiting reagent because 6.28 g CaCl2 are required to react with 6.0 g Na2CO3

while only 4.0 g CaCl2 are available. Therefore, Na2CO3 is in excess (the excess reagent).

? mol CaCl2 = 4.0 g CaCl2

= 0.036 mol CaCl2

# mol CaCO3 = 0.036 mol CaCl2 (since it is the limiting reagent & the ratio is 1:1)

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? g CaCO3 = 0.036 mol CaCO3 x

= 3.6 g CaCO3

Percent Yield =

x 100

=

x 100

= 72.22%

*Conclusion:

In conclusion, this experiment allowed us to visualize the formation of a precipitate, which

in this case was CaCO3, and calculate its mass after filtering a mixture consisting of two

solutions. Moreover, it allowed us to further our knowledge concerning the process of

filtration, as well as developed our skills in observation, analysis, and stoichiometric

calculations.

*Evaluation & Improvements:

In general, the experiment was nearly perfect. However, in order to improve the

experiment as a whole, as well as its accuracy and reliability, more accurate balances can

be used as well as purer forms of the substances and solutions. Also the use of desiccators

would play a significant role in keeping the precipitate formed in a nearly absolute pure

form which would therefore lead to a more accurate reading of the mass of precipitate

obtained.