For a chemistry lab the experiment was to carry out an acid-base titration to determine the exact concentration of a sodium hydroxide solution.
Two trials were completed and the data collected was: mass of weighing paper, mass of weighing paper + KHP, mass of KHP, initial buret reading, final buret reading, and volume of NaOH.
The molecular weight of KHP is 204.44 grams/mol.
I need to find the number of moles of KHP, the number of moles of NaOH and the concentration of NaOH but i am not sure how to do this. Please help,thank you!!
I answered this at your first post below.
To find the number of moles of KHP (potassium hydrogen phthalate), you can use the formula:
Number of moles = Mass of KHP / Molecular weight of KHP
Given that you have the mass of KHP, which is one of the data points collected, and you know the molecular weight of KHP (204.44 grams/mol), you can substitute these values into the formula to find the number of moles of KHP.
Next, to find the number of moles of NaOH (sodium hydroxide), you can use the balanced chemical equation between KHP and NaOH:
1 mole of KHP reacts with 1 mole of NaOH
Since the stoichiometry is 1:1, the number of moles of NaOH will be the same as the number of moles of KHP.
Now, let's calculate the number of moles of KHP and NaOH for each trial using the data provided:
Trial 1:
- Mass of KHP (mKHP) = mass of weighing paper + KHP - mass of weighing paper
- Number of moles of KHP (nKHP) = mKHP / molecular weight of KHP
Trial 2:
- Mass of KHP (mKHP) = mass of weighing paper + KHP - mass of weighing paper
- Number of moles of KHP (nKHP) = mKHP / molecular weight of KHP
Since the stoichiometry between KHP and NaOH is 1:1, the number of moles of NaOH will be the same as the number of moles of KHP for both trials:
Number of moles of NaOH = number of moles of KHP for each trial
To find the concentration of NaOH, you can use the formula:
Concentration (M) = Number of moles / Volume (in liters)
Given that you have the volume of NaOH for each trial, you can substitute the number of moles of NaOH into the formula to find the concentration of NaOH for each trial.