Final answer:
To completely react with 0.450 g of Na₂CO₃, you would need 0.00849 mol of 0.100 m HNO₃.
Step-by-step explanation:
To determine the amount of 0.100 m HNO₃ needed to completely react with 0.450 g of Na₂CO₃ (105.99 g/mol), we need to first convert the mass of Na₂CO₃ to moles using its molar mass:
Moles of Na₂CO₃ = 0.450 g / 105.99 g/mol = 0.00424 mol.
Since the stoichiometric ratio between HNO₃ and Na₂CO₃ is 2:1, this means that:
Moles of HNO₃ needed = 0.00424 mol × 2 = 0.00849 mol.
Therefore, 0.00849 mol of 0.100 m HNO₃ is needed to completely react with 0.450 g of Na₂CO₃.