chem question help 22-2

Question

How many moles of hydrogen carbonate need to decompose to produce 8.26 x 10²³ molecules of carbon dioxide if water is the only other product? Give your answer in scientific notation.

Answer 1

Decomposition reaction of hydrogen carbonate:

H₂CO₃ → H₂O + CO₂

Use avogadro's # and stoichiometry to convert # of molecules of CO₂ to moles of H₂CO₃.

molecules CO₂ → mol CO₂ → mol H₂CO₃

8.26 x 10²³ molecules CO₂ x (1 mol CO₂ / 6.02 x 10²³ molecules CO₂) x (1 mol H₂CO₃ / 1 mol CO₂) = 1.37 mol H₂CO₃ (rounded to 3 significant figures) = 1.37 x 10⁰ mol H₂CO₃ (in scientific notation)