Stoich: Baking Soda and Vinegar


The chemical reaction between acetic acid and sodium bicarbonate is modeled below:

HC2H3O2(aq) + NaHCO3 (s) –> NaC2H3O2(aq) + CO2(g) + H2O(l)

The experiment was performed in class to model relationships of moles and their importance in stoichiometry.

In the lab performed no matter was created nor destroyed. The matter in the beginning of the experiment was either converted to sodium acetate, water, carbon dioxide or simply left unreacted due to a limiting reactant. This is modeled in the graph below, as the vinegar and baking soda reaction produces a steady flow of carbon dioxide in till there is no more vinegar in the solution to react with the baking soda meaning that all matter is accounted for either as baking soda, sodium acetate, water, or carbon dioxide. This shows the conservation of mass as no matter was created nor destroyed.

The stoichiometric relationships in this lab are the coefficients in front of the chemicals in the balanced chemical reaction showing the molar ratios between the substances.

HC2H3O2(aq) + NaHCO3 (s) –> NaC2H3O2(aq) + CO2(g) + H2O(l)

In this lab the ratio between all chemicals is 1:1 moles, meaning for every one mole of sodium bicarbonate reacted one mole of carbon dioxide will be produced.

The limiting reactants in this experiment switch between the baking soda and vinegar. This is modeled in the graph, but basically in the beginning of the experiment the baking soda is the limiting reactant as the vinegar reacts with all the baking soda in the solution. But as we gradually increase the amount of baking soda in solution the baking soda stops reacting because all the vinegar had been used up in the solution reacting to the baking soda now becoming the new limiting reactant. That is how both agents can be either the limiting or excessive reactant.

How to calculate stoich:

1. Get to moles

2. Mole ratio

3. Get out of moles

First take the grams of both reactants and convert to moles. Multiply by the ratio of the moles of the reactants and moles of one of the products same for both. Which ever reactant has the smaller mole number is the limiting reactant(Begin from the beginning steps with the limiting reactant to find the moles of other products).



About chriscatanach

I enjoy long walks on the beach and watching the sun set. I am in a long term relationship with math and science. The movies are what I consider a man-made heaven. Most of all I think my self out to be the fictional reincarnation of Jay Gatsby.
This entry was posted in Uncategorized and tagged , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s