Chemistry – Stoichiometry - The mole and the Avogadro constant | e-Consult
Stoichiometry - The mole and the Avogadro constant (1 questions)
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Calculation:
- Calculate the moles of Na2CO3 used: moles = concentration x volume (dm3). Volume of Na2CO3 = 20.0 cm3 = 0.020 dm3. Concentration = 0.100 mol/dm3. Therefore, moles of Na2CO3 = 0.100 mol/dm3 x 0.020 dm3 = 0.002 moles.
- Use the stoichiometry of the reaction to find the moles of HCl: From the balanced equation, 1 mole of Na2CO3 reacts with 2 moles of HCl. Therefore, moles of HCl = 0.002 moles Na2CO3 x (2 moles HCl / 1 mole Na2CO3) = 0.004 moles HCl.
- Calculate the concentration of the HCl solution: Concentration = moles / volume (dm3). Volume of HCl solution = 25.0 cm3 = 0.025 dm3. Therefore, concentration of HCl = 0.004 moles / 0.025 dm3 = 0.16 mol/dm3.
Answer: The concentration of the HCl solution is 0.16 mol/dm3.