Calculate the sodium ion concentration when 45.0 mL of 2.5 M sodium cabonate is added to 30.0 mL of 1.0 M sodium bicarbonate.
mols Na2CO3 = M x L. Mols Na^+ = twice that.
mols NaHCO3 = M x L. Mols Na^+ = 1 x that.
Total Na = sum of the two.
To calculate the sodium ion concentration, we'll first find the number of moles of sodium ions in sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3).
Step 1: Calculate the moles of sodium carbonate (Na2CO3):
Moles of Na2CO3 = Molarity of Na2CO3 x Volume of Na2CO3
Moles of Na2CO3 = 2.5 M x 0.045 L
Moles of Na2CO3 = 0.1125 moles
Step 2: Calculate the moles of sodium ions in sodium carbonate:
Moles of Na+ in Na2CO3 = 2 x Moles of Na2CO3
Moles of Na+ in Na2CO3 = 2 x 0.1125 moles
Moles of Na+ in Na2CO3 = 0.225 moles
Step 3: Calculate the moles of sodium bicarbonate (NaHCO3):
Moles of NaHCO3 = Molarity of NaHCO3 x Volume of NaHCO3
Moles of NaHCO3 = 1.0 M x 0.030 L
Moles of NaHCO3 = 0.030 moles
Step 4: Calculate the moles of sodium ions in sodium bicarbonate:
Moles of Na+ in NaHCO3 = 1 x Moles of NaHCO3
Moles of Na+ in NaHCO3 = 1 x 0.030 moles
Moles of Na+ in NaHCO3 = 0.030 moles
Step 5: Find the total moles of sodium ions:
Total moles of Na+ = Moles of Na+ in Na2CO3 + Moles of Na+ in NaHCO3
Total moles of Na+ = 0.225 moles + 0.030 moles
Total moles of Na+ = 0.255 moles
Step 6: Calculate the sodium ion concentration:
Sodium ion concentration = Total moles of Na+ / Total volume
Total volume = Volume of Na2CO3 + Volume of NaHCO3
Total volume = 0.045 L + 0.030 L
Total volume = 0.075 L
Sodium ion concentration = 0.255 moles / 0.075 L
Sodium ion concentration = 3.4 M
Therefore, the sodium ion concentration when 45.0 mL of 2.5 M sodium carbonate is added to 30.0 mL of 1.0 M sodium bicarbonate is 3.4 M.