5. Using the equation moles = mass (g) /molar mass find the moles of sodium carbonate. Remember, you used 5 grams!

Answer 1

molar mass sodium carbonate (Na₂CO₃) = 105.99 g/mol

moles = mass(g) / molar mass

moles = 5 g / 105.99 g/mol

moles = 0.047 moles = 0.05 moles (1 significant figure)

Now, if you are referring to a previous question you posted where you used 5 g of sodium bicarbonate (NaHCO₃), that's different from sodium carbonate (Na₂CO₃). The molar mass of sodium bicarbonate = 84 g/mole

moles = 5 g/84 g/mol = 0.06 moles (1 significant figure)