How can I determine the concentration of HCl remaining in the flask after back titration?
PLEASE SHOW SOLUTION!!!!!!
Con. of HCl: 0.14M
Volume added:100mL
Con. of NaOH:0.145M
Weight of Tablet: 1.0g
I have been given weight of antacid, concentration and volume of HCl and concentration of NaOH. I've done 3 trials and found the average volume of NaOH.
I've answered this question twice. Instead of posting a generic question (at least partly generic) why don't you include the volume of NaOH used in the back titration. That way we can talk reality instead of do this/ do that.
To determine the concentration of HCl remaining in the flask after back titration, you will need to follow several steps. Here's how you can calculate it:
Step 1: Calculate the moles of HCl titrated:
To do this, you need to use the balanced chemical equation between HCl and NaOH:
HCl + NaOH -> NaCl + H2O
Based on the balanced equation, the stoichiometric ratio between HCl and NaOH is 1:1. This means that 1 mole of HCl reacts with 1 mole of NaOH.
To calculate the moles of HCl titrated, you can use the concentration and volume of NaOH (which you mentioned you have already calculated the average volume). Multiply the average volume of NaOH (in liters) by its concentration (in moles per liter). This will give you the moles of NaOH.
Moles of NaOH = Volume of NaOH (in L) x Concentration of NaOH (in M)
Step 2: Calculate the moles of excess NaOH:
Since the stoichiometric ratio is 1:1, the moles of NaOH titrated in Step 1 are equal to the moles of HCl titrated.
Step 3: Calculate the moles of HCl in the original solution:
To calculate the moles of HCl in the original solution, you can use the moles of excess NaOH (which is equal to the moles of HCl titrated). Again, the stoichiometric ratio of 1:1 applies here.
Moles of HCl = Moles of Excess NaOH
Step 4: Calculate the concentration of HCl remaining:
Finally, to determine the concentration of HCl remaining, you need to divide the moles of HCl by the final volume of the HCl solution (after the back titration) in liters.
Concentration of HCl remaining = Moles of HCl / Volume of HCl (in L)
Remember to convert all volumes to liters and ensure units are consistent throughout the calculations.
By following these steps, you can determine the concentration of HCl remaining in the flask after back titration.