A .7567 impure KHP was dissolved in water. 26.7 ml of standardized 0.068 M NaOH was used to achieve a phenolphthalein end point. The stoichiometric ratio between KHP and NaOH is 1:1.
What is the percent by mass of KHP in the sample?
mols NaOH = M x L = estimated 0.0018
Therefore, mols KHP = estimated 0.0018
g KHP = mols KHP x molar mass KHP = ?
% KHP = (mass KHP.mass sampe)*100 = ?
To find the percent by mass of KHP in the sample, we need to determine the mass of KHP and the total mass of the sample.
First, let's calculate the number of moles of NaOH used. We can use the formula:
moles (NaOH) = volume (NaOH) × concentration (NaOH)
moles (NaOH) = 26.7 ml × 0.068 mol/ml = 1.8136 mol
Since the stoichiometric ratio between KHP and NaOH is 1:1, the moles of KHP used will also be 1.8136 mol.
Now we can find the mass of KHP used. The molar mass of KHP (KHC8H4O4) is 204.23 g/mol.
mass (KHP) = moles (KHP) × molar mass (KHP)
mass (KHP) = 1.8136 mol × 204.23 g/mol = 370.927 g
However, we are told that the KHP used in the sample is impure, with an impurity of 0.7567. To find the mass of pure KHP, we need to subtract the impurity mass.
mass (pure KHP) = mass (KHP) - impurity mass
mass (pure KHP) = 370.927 g - 0.7567 g = 370.1703 g
Finally, we can calculate the percent by mass of KHP in the sample.
percent by mass (KHP) = (mass (pure KHP) ÷ total mass of sample) × 100
percent by mass (KHP) = (370.1703 g ÷ total mass of sample) × 100
Please provide the total mass of the KHP sample to continue the calculation.