Thermochemistry Invisible Ink Sodium Nitrate

Edit Experiment

VIDEO LINKS:

Lab Experiments (Write protocols based on the videos then complete your protocols as you perform experiments in class):

Invisible Ink with Sodium Nitrate

Data analysis and calculations (Use these if you need help with your data and calculations)

Fire

Experimental Protocol

(Analysis) Write out the protocol for each part of the experiment.  (It can be written in sequential steps.  Complete sentences are not necessary.)  This is the protocol you follow, so be detailed.

Chemical Table

(Representation) Prepare your chemical table including the materials you use in the experiment.  Here is a general template that you may use.
Chemical Name Chemical Formula Molar Mass (g/mol) Hazards Reference PPE
Sodium Chloride NaCl 58.5 Skin irritation https://fscimage.fishersci.com/msds/21105.htm  
           
           
           

Equipment Table

(Analysis) Identify the equipment (type AND size) needed for the experiment and include the name and an image (picture) of each.  Be sure to describe the equipment, how to use it, and why it is suitable for this use.
Equipment Name Equipment Picture Intended Purpose

Data Collection

(Acquiring competencies) Following your detailed protocol, perform all the experiments. Record your observations and take pictures of your key steps in the process. Your observations and images need to be incorporated in your data section and this section should be as detailed as possible as you will use this information to complete your discussion.

Data Processing

  1. (Representation) Cellulose in the filter paper reacts with oxygen, a decomposition product of sodium nitrate. Write the chemical reaction to show the combustion of the filter paper.
  2. (Analysis) Select all that apply. Sodium nitrate is:
    An atom An ionic compound
    An element Soluble in water
    A molecule Able to react with itself
    A compound Only able to react with other materials
    An organic compound Crystalline
    An inorganic compound  Amorphous
  3. (Analysis) Select all that apply. Paper is:
    An atom An ionic compound
    An element Soluble in water
    A molecule Able to react with itself
    A compound Only able to react with other materials
    A mixture Crystalline
    An organic compound  Amorphous
    An inorganic compound
  4. (Analysis) For the black snake experiment, comment on whether the volume is increasing, decreasing, or remaining the same based on your observations.
  5. (Analysis) Looking at the product of the black snake experiment, estimate its composition.
  6. (Analysis) For the experiment, identify the it as spontaneous or non-spontaneous and provide your reasoning.
  7. (Analysis) For the experiment, identify it as endothermic (heat is absorbed to make a change) or exothermic (heat is given off in the process of a change) and provide your reasoning.
  8. Fill in the following table using the data and observations from your experiment:
    Assumptions made Testing the assumption If assumptions are wrong ...
    The distilled water is pure Evaporate it and check for residue
    Sugar is pure

Discussion

Write a minimum one-page (12 font, single spaced) discussion on the experiment conducted this week.  The assignment will be graded on completeness, clarity of the explanations and the meaningful integration of the collected and calculated data. Correct grammar and appropriate format for the chemical formulae and chemical reactions is expected. You may use the outline included at the end of this document on how to build your essay to address each category.  
  1. (Analysis) Classify the invisible ink experiment as a physical or chemical change and justify your choice.
  2. (Analysis) Based on your observations, give a supported prediction as to whether the mass of the product would be greater or less than the starting material in this experiment.
  3. (Existing knowledge, research, and views) List the 3 components of fire and identify each one in the invisible ink experiment.
  4. (Analysis) Provide a supported argument for why drying the paper in the invisible ink experiment was necessary.
  5. (Analysis) Identify any similarities between the fuels used this experiment and a wood burning fireplace.
  6. (Experimental Design) Design an experiment to test for a change in mass during the burning process.
  7. (Analysis) Identify at least two reasons for not closing shapes in the invisible message.

Recommended Discussion Outline:

The techniques I used in this experiment were… This lab is considered qualitative because… In this experiment we assumed .... The purpose of the experiment was (Hint: it was not to cook) … By performing this experiment, I learned…