Principlesof Chemistry Lab ILF 7 Limiting Reactants 193242 PDF

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Principlesof Chemistry Lab ILF 7 Limiting Reactants 193242...

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Principles of Chemistry Lab I - LF7 Limiting Reactants Final Report Student Name

Marleny Mendoza

Student ID

193242

Lesson

Limiting Reactants

Institution

SUNY at Old Westbury

Session

Fall 2021

Course

Principles of Chemistry Lab I - LF7

Instructor

Lori Zaikowski

Test Your Knowledge 1. Nitrogen and hydrogen react to form ammonia:

Identify the limiting reactant (hydrogen or nitrogen) in each of the followingcombinationsof starting chemicals.

Limiting Reactant: Hydrogen

Limiting Reactant: Nitrogen

1

2

1.0 mole of nitrogen and 1.0 mole of hydrogen

0.75 moles of nitrogen and 2.5 moles of hydrogen 1.0 mole of nitrogen and 4.0 moles of hydrogen 10.0 grams of nitrogen and 10.0 grams of hydrogen

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2. Label each type of reaction.

1

Double displacement

2

Decomposition

3

Combination

4

Single displacement

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3. Move the terms to complete each statement.

A 1

Chemical equation

describes a reaction that occurs between two or

more chemical substances.

A chemical substance that participates and undergoes change in a chemical reaction is called a 2

Reactant

3

Stoichiometry

.

can be used to determine how much of each

reactant is needed to produce a specific amount of each product.

The reactant that is consumed first is referred to as the 4

Limiting reactant

The 5

Law of conservation of mass

.

states that the total mass, in a closed system,

does not change as the result of reactions between its parts.

Exploration 1. The substances that interact in a reaction are called reactants, while the substances produced from the reaction are called products. True False

2. The proportion of reactants to products can be calculated using a balanced chemical equation and stoichiometry. True False

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3. A _____ reaction occurs whenan uncombined element displaces an element in acompound. decomposition combination single displacement double displacement

4.In a chemical reaction, the reactant that is consumed first is referred to as the _____. stoichiometry smaller reactant limiting reactant balanced equation limiting product

5. In the chemical equation

,if calcium is the limiting

reactant, then _____ will be in excess. Ca O2 CaO no substances

6. The law of conservation of massstates that _____. the total mass, in an open system, does not change as the result of reactions between its parts the total mass, in a closed system, does not change as the result of reactions between its parts particles at rest tend to stay at rest the total energy of an isolated system cannot change

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Exercise 1 1. From your calculations, which reaction experiment had closest to stoichiometric quantities? How many moles of NaHCO3 and HC2 H3 O2 were present in this reaction? The closest experiment is balloon 3. Because, it has a similar mol values for each reactive.

2. The chemical reaction you investigated is a two-step reaction. What type of reaction occurs in each step? How did you determine your answer? In the first reaction:CH3COOH + NaHCO 3-> H 2CO 3+ CH 3COONa In this case, it has a double replacement reaction. Because the "H" is exchange y the "Na" in both compounds.

In the second reaction:H 2CO 3-> CO 2+ H 2O

In this case, It has a decomposition reaction because we have only 1 reactive and 2 products.

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3. As the reaction was theoretically performed in a closed system, there should be no change in mass before and after thereaction. What are possible sources of error in your experiment reactions? possible reasons to the variability in the mass in a theoretically closed system, could be:

a) Error in the measurement of the reagents.

b) Problems or leakage in the system.

c) Temperature variation in the system, in these experiments temperature are not given.

4. What is the relationship between the limiting reactant and theoretical yield of CO2 ? The CO2amount according with limiting reagent is lesser in comparison with mol amount of NaHCO3

5. After the reactions occurred, did the largest balloon size match the largest theoretical yield you calculated in Data Table 4? Use your experimental results to explain your answer.If not, what sources of error do you think caused the discrepancy? I believe it did match the largest theoretical yield since there was a larger quantity of sodium bicarbonate.

Data Table 1: Conservation of Mass – Initial Mass

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Reaction #

Massoftest tubeand5% HC2 H3O2(g) (A)

1

14.45 g

2

14.54 g

3

14.47 g

4

14.39 g

Reaction #

MassofNaHCO3 (g) (B)

1

0.10

2

0.20

3

0.35

4

0.50

Reaction #

Massof balloonandNaHCO3(g) (C)

1

1.80 g

2

1.81 g

3

1.85 g

4

1.99 g

Reaction #

Total mass before reaction(g) (D = A + C)

1

16.25

2

16.35

3

16.32

4

16.38

Data Table 2: Moles of HC2H3O2

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Reaction #

Volume of 5% Vinegar (mL)

Mass of HC2 H3 O2 (g)

Moles of HC2H3O 2

1

5.0

0.25

0.0042 moles

2

5.0

0.25

0.0042 moles

3

5.0

0.25

0.0042 moles

4

5.0

0.25

0.0042 moles

Data Table 3: Moles of NaHCO3 Reaction #

Mass of NaHCO3 (g)

Moles of NaHCO3

1

0.3497 g

0.0042 moles

2

0.3497 g

0.0042 moles

3

0.3497 g

0.0042 moles

4

0.3497 g

0.0042 moles

Data Table 4: Theoretical Yield of CO2

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Reaction #

Limiting Reactant

1

NaHCO3

2

NaHCO3

3

NaHCO3

4

CH3 COOH

Reaction #

Theoretical yield of CO 2 (moles)

1

0.00218 mol

2

0.00218 mol

3

0.00218 mol

4

0.00218 mol

Reaction #

Theoretical yield of CO2 (g)

1

0.18318 g

2

0.18318 g

3

0.18318 g

4

0.18318 g

Panel 1: Hypothesis Since all the reactions 1,2,3 and 4 produce equivalent volumes of CO 2, all of the balloons will expand equally.

Photo 1: Reaction Results

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Data Table 5: Conservation of Mass

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Reaction #

Total Mass after Reaction (g) (E)

Mass Difference (g) (F = D - E)

1

16.198 g

16.25-16.98=0.052 g

2

16.245 g

16.35-16.245=0.105 g

3

16.163 g

16.32-16.163=0.157 g

4

16.197 g

16.38-16.197=0.183 g

Competency Review 1. In the chemical equation

, 4Fe is considered a _____.

reactant product compound

2. Stoichiometry can be applied to a chemical equation to calculate _____. the half-life of an element significant digits based on SI units activation energy in relation to chemical reactivity the proportion of reactants and products

3. When chlorine reacts with sodium iodide to form sodium chlorideand iodine, a _____ reaction takes place. combination decomposition single displacement double displacement

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4. Consider a closed system in whichaluminum sulfate and sodium hydroxide react to form aluminum hydroxide and sodium sulfate. Ifaluminum sulfateis the limiting reactant, what other information can be concludedabout the substances? the reaction rate will decrease the sodium hydroxide will be found in excess the reverse reaction will be favored a single displacement reaction will proceed

5. The law of conservation of mass states that the total mass, in a closed system, does not change as the result of reactions between its parts. True False

6. The law of conservation of mass states that the total mass in a closed chemical system does not change. In a student experiment, initial mass might differ from final mass due to experimental error. True False

7. If 0.00416 mols of HC2 H3 O2 are reacted with 0.00595 mols of NaHCO3 ,_____ is/are considered a limiting reactant. HC 2H 3O 2 and NaHCO 3 NaHCO3 HC 2H 3O 2 the products no chemicals

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8. Percentyield can be calculated by dividing actual yield by theoretical yield and multiplying by 100. True False

Extension Questions 1. 2Al(s) + 3H2 SO4 (aq)→ Al2 (SO4 )3 (aq) + 3H2 (g) a. Determine the volume (mL) of 15.0 M sulfuric acid needed to react with 45.0 g of aluminum to produce aluminum sulfate. b. Determine the % yield if 112 g of aluminum sulfate is produced under the aboveconditions. Volume in L=(15)x(2.50 moles of H2SO4) =0.1666 L (166.66 ml) of H2SO4 is required

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