Pre-Lab: Mole Relationship in a Chemical Reaction



Pre-Lab: Mole Relationship in a Chemical Reaction

Read the lab procedure and answer the following pre-lab questions in your lab notebook in complete sentences.

1. Define the Law of Conservation of Conservation of Mass and Energy.

2. How does this law apply to chemical equations?

3. What do the coefficients represent in a balanced equation?

4. Why is it not always convenient to determine the mass of all substances involved in a chemical reaction?

5. What are the reactants in this lab?

6. Read Conclusion #1. What do you hypothesize are the products of this reaction? Why are you evaporating the products?

7. Based on your answers for 5 and 6 above, write a balanced equation for this lab.

8. What is the mole ratio between NaHCO3 and NaCl?

9. Below is a sample data table. Prepare one for your use in your lab notebook. Complete the table below, showing all calculations in your lab notebook.

|1. Mass of empty evaporating dish | 98.24 g |

|2. Mass of dish and NaHCO3 |102.45 g |

|3. Mass of NaHCO3 | |

|4. Moles of NaHCO3 | |

|5. Mass of dish and NaCl |101.22 g |

|6. Mass of NaCl | |

|7. Moles of NaCl | |

|8. Mole ratio NaHCO3 : NaCl | |

Post Lab

Mole Relationship in a Chemical Reaction

1. Write the balanced equation for the reaction.

2. What is the theoretical mole ratio of NaHCO3 to NaCl?

3. Fill in the data table using your lab data and show all your calculations.

4. What is your experimental mole ratio of NaHCO3 to NaCl? Does this agree with the balanced equation?

5. From your date table answer for the mass of NaHCO3 used in the lab, determine the mass of NaCl you should have produced in the experiment (theoretical mass of NaCl). Show your work. This is a mass-mass problem.

6. From your data table answer for the experimental mass of NaCl and the theoretical mass of NaCl [from #5] above, determine the percentage error in your experiment. Show your work

Data Table

|1. Mass of empty evaporating dish | |

|2. Mass of dish and NaHCO3 | |

|3. Mass of NaHCO3 | |

|4. Moles of NaHCO3 | |

|5. Mass of dish and NaCl | |

|6. Mass of NaCl | |

|7. Moles of NaCl | |

|8. Mole ratio NaHCO3 : NaCl | |

Show all calculations:

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Name _______________________________

Date ____________________ Block ______

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