Calculate the number of liters of CO2 that are produced by heating 35.1 g of sodium hydrogen carbonate.

Question

I don't know where to start

Answer 1

Always start by writing the chemical reaction equation. I'm assuming here that we are talking about the decomposition of sodium hydrogen carbonate (NaHCO₃). To start with, don't worry about balancing it, just get all the elements/compounds in it. So we know that the left side will have NaHCO3 and the right side will have CO₂ so what else is left for the right side? Well there's hydrogen and an oxygen. I'll bet that will form water. There's also a sodium and it makes sense that the sodium would combine with some negative ion or polyatomic ion to form an ionic bond. That will be carbonate CO₃^2- and since sodium is a +1 charge, there must be two sodium atoms so Na₂CO₃ making the basic (unbalanced) equation:

NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

Step 2, balance it by adding a 2 on the left in front of NaHCO₃:

2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

Step 3: Calculate the number of moles of 1) 35.1 g of NaHCO₃ and then 2) of the resulting CO₂

Calculate the molar mass of NaHCO₃ by adding 22.990(1) (Na x 1) and 1.008(1) (H x 1) and 12.011(1) (C x 1) and 15.999(3) (O x 3) to get 84.006 g/mol.

Divide 35.1 g by 84.006 g/mol to get 0.4178 moles of NaHCO₃

Using the balanced chemical reaction equation, we see that for every 2 moles of NaHCO₃ , 1 mole of CO₂ is produced so divide the number of moles of NaHCO₃ in half to get the number of moles of CO₂. 0.4178/2 = 0.2089 moles of CO₂.

Step 4. Convert moles of an ideal gas to liters of an ideal gas using the conversion factor of 22.4 Liters/1 mole. Multiplying 0.2089 moles of CO₂ by 22.4 Liters/1 mole we get 4.68 L of CO₂.