My picture; Baking Soda and Vinegar

My picture; Baking Soda and Vinegar

Today and yesterday, we mixed sodium bicarbonate and sodium carbonate with acetic acid (vinegar) and sulfuric acid. Here are the balanced equations of those mixes (except for the last one, which we didn’t experiment with), with coefficients in bold:

Sodium bicarbonate + acetic acid: NaHCO3 + HC2H3O2 -> CO2+ H2O+ NaC2H3O2

Sodium carbonate + acetic acid: Na2CO3 + 2HC2H3O2 -> CO2+ H2O+ 2NaC2H3O2

Sodium bicarbonate + sulfuric acid: 2NaHCO3 + H2SO4 -> 2CO2+ 2H2O+ Na2SO4

Sodium carbonate + sulfuric acid: Na2CO3 + H2SO4 -> CO2+ H2O+ Na2SO4

My picture, a reaction

My picture, a reaction

 

In each one, the mass of the lost gas (carbon dioxide) must be calculated from other masses taken if the reaction isn’t in a sealed container, and the mass depends on the amount of solid present in the reaction. Here are the relationships for each mix:

1. 44.01g CO2 / 84.008g NaHCO3
2. 44.01g CO2 / 105.98g Na2CO3
3. 88.02g CO2 / 168.016g NaHCO3. Or, 44.01g CO2 / 84.008g NaHCO3
4. 44.01g CO2 / 105.98g Na2CO3

My picture; dangerous Sulfuric Acid :D

My picture; dangerous Sulfuric Acid 😀

 

So from this data, seemingly, the only factor in the ratio of gas produced is the type of solid in the reaction, whether sodium bicarbonate or carbonate or any other solid and gas, and so a solid-to-gas ratio would probably apply to any/all chemical reactions of this nature.

One final thing that is important to say, and that is that because a fixed amount of solid produces a fixed amount of gas, then a fixed number of solid molecules will produce a fixed number of gas molecules, so their molar quantities are also in a relationship. Their molar quantities must also be related because equal masses of solid and gas have different numbers of molecules, so we can’t know how many solid molecules will be left over after the reaction unless we know the actual number of atoms or moles of each substance there is. That is also evident in the coefficients of the equations above; one mole of sodium bicarbonate and one mole of acetic acid will produce one mole each of carbon dioxide, water, and sodium acetate; two moles of sodium bicarbonate and one of sulfuric acid begets two moles of carbon dioxide, two of water, and one of sodium sulfate, etc. That also explains why the molar relationships above use the molar masses of the solids and gases (and why the third one had two ratios: the first, based on the molar masses and the coefficients, and the second one, because they are both reducible by 2).

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