To calculate the percentage of potassium chloride in the mixture, we first need to determine the moles of potassium chloride and potassium carbonate in the solution.
1. Moles of potassium chloride (KCl):
Molar mass of KCl = 39.10 + 35.45 = 74.55 g/mol
Moles of KCl = 9.57g / 74.55 g/mol = 0.1282 moles
2. Moles of potassium carbonate (K2CO3):
Molar mass of K2CO3 = 2(39.10) + 12.01 + 3(16.00) = 138.21 g/mol
From stoichiometry, 1 mole of K2CO3 forms 2 moles of KCl
Moles of K2CO3 = 0.1282 moles KCl x (1 mole K2CO3 / 2 moles KCl) = 0.0641 moles
3. Total moles of KCl and K2CO3:
Total moles in 0.5 L solution = moles / volume in L
Total moles = 0.1282 moles + 0.0641 moles = 0.1923 moles in 0.5 L solution
4. Moles of acid used in the titration:
Moles of acid = concentration x volume in L
Moles of acid = 0.25 mol/L x 0.015 L = 0.00375 moles
5. From the titration reaction, 1 mole of acid reacts with 1 mole of KCl:
Moles of KCl = 0.00375 moles
6. Calculate the percentage of potassium chloride:
Percentage of KCl = (moles of KCl / total moles) x 100%
Percentage of KCl = (0.00375 moles / 0.1923 moles) x 100%
Percentage of KCl = 1.95%
Therefore, the percentage of potassium chloride in the mixture dissolved in distilled water is 1.95%.
A form four student dissolved 9.57g of potassium chlonde and potassium carbonate in distilled water to make it half a litre of solution. She pipetted 20cm³ of this solution into a comical flask and titrated it against monobasic acid of concentration 0.25M using phenolphthalein indicator. the volume of acid used was 15 cm³. calculate the percentage of potassium chloride in the mixture dissolved in distilled water
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