25cm3 of 0.1mol/dm3 Na2CO3 solution was titrated against 23.45cm3 of H2SO4 acid using phenolphthalein indicator. Calculate the concentration of the acid.
To calculate the concentration of the acid (H2SO4), we can use the balanced chemical equation and stoichiometry of the reaction that occurs between Na2CO3 and H2SO4:
Na2CO3 + H2SO4 → Na2SO4 + H2O + CO2
From the balanced equation, we can see that the stoichiometric ratio between Na2CO3 and H2SO4 is 1:1. This means that for every 1 mole of H2SO4, we need 1 mole of Na2CO3 to react completely.
Given the volume of the Na2CO3 solution (25 cm3) and its concentration (0.1 mol/dm3), we can calculate the number of moles of Na2CO3 as follows:
moles of Na2CO3 = volume (dm3) * concentration (mol/dm3)
= 25 cm3 / 1000 cm3/dm3 * 0.1 mol/dm3
= 0.0025 mol
Since the stoichiometric ratio between Na2CO3 and H2SO4 is 1:1, we know that the number of moles of H2SO4 required for complete reaction is also 0.0025 mol.
Now, let's calculate the concentration of the H2SO4 acid:
concentration of H2SO4 (mol/dm3) = moles of H2SO4 / volume of H2SO4 (dm3)
To find the volume of the H2SO4 solution, we'll subtract the initial and final burette readings:
volume of H2SO4 = final burette reading - initial burette reading
= 23.45 cm3 - 0 cm3
= 23.45 cm3
Converting the volume to dm3:
volume of H2SO4 (dm3) = 23.45 cm3 / 1000 cm3/dm3
= 0.02345 dm3
Now we can calculate the concentration of H2SO4:
concentration of H2SO4 (mol/dm3) = 0.0025 mol / 0.02345 dm3
≈ 0.1067 mol/dm3.
Therefore, the concentration of the H2SO4 acid is approximately 0.1067 mol/dm3.
To calculate the concentration of the acid (H2SO4), we can use the balanced equation of the reaction and the stoichiometry of the reactants.
The balanced equation for the reaction between Na2CO3 (sodium carbonate) and H2SO4 (sulfuric acid) is:
Na2CO3 + H2SO4 -> Na2SO4 + H2O + CO2
From the balanced equation, we can see that one mole of Na2CO3 reacts with one mole of H2SO4. Since we know the volume and concentration of the sodium carbonate solution, we can calculate the number of moles of Na2CO3 as follows:
Moles of Na2CO3 = Volume of Na2CO3 solution (in dm3) x Concentration of Na2CO3 solution (in mol/dm3)
Moles of Na2CO3 = 25 cm3 x (1/1000) dm3/cm3 x 0.1 mol/dm3
Moles of Na2CO3 = 0.0025 mol
Since the stoichiometry of the balanced equation is 1:1 for Na2CO3 and H2SO4, the number of moles of H2SO4 present in the solution is also 0.0025 mol.
Now, we can use the number of moles of H2SO4 and the volume of H2SO4 solution to calculate its concentration:
Concentration of H2SO4 = Moles of H2SO4 / Volume of H2SO4 solution (in dm3)
Concentration of H2SO4 = 0.0025 mol / (23.45 cm3 x (1/1000) dm3/cm3)
Concentration of H2SO4 = 0.1066 mol/dm3
Therefore, the concentration of the sulfuric acid (H2SO4) is approximately 0.1066 mol/dm3.