9.3 - Estimation of Total Hardness using Ethylenediaminetetraacetic Acid (Leaving Cert Chemistry): Quizzes
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12 questions from this quiz
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Practise the questions
12 questions from this quiz
Which ions contribute to total hardness in water?
Which ions contribute to total hardness in water?
and
What indicator is used to detect the endpoint in EDTA titration for water hardness?
What indicator is used to detect the endpoint in EDTA titration for water hardness?
Eriochrome Black T
What color change indicates the endpoint of the titration?
What color change indicates the endpoint of the titration?
Wine-red to blue
What pH should the buffer solution maintain during the titration?
What pH should the buffer solution maintain during the titration?
10
What volume of hard water sample is pipetted into the conical flask?
What volume of hard water sample is pipetted into the conical flask?
50 cm³
What mass of Eriochrome Black T indicator is added to the flask?
What mass of Eriochrome Black T indicator is added to the flask?
0.03 g
What is the safety classification of EDTA?
What is the safety classification of EDTA?
Harmful
What is the stoichiometric ratio between EDTA and metal ions in the reaction?
What is the stoichiometric ratio between EDTA and metal ions in the reaction?
1:1
Why is a pH 10 buffer solution used in this experiment?
Why is a pH 10 buffer solution used in this experiment?
Ensures stable complexes form with ions
How would or ions affect the total hardness value?
How would or ions affect the total hardness value?
Cause overestimation
How can permanent hardness be determined from the water sample?
How can permanent hardness be determined from the water sample?
Boil sample, then titrate remainder
What defines concordant results in this titration?
What defines concordant results in this titration?
Within 0.1 cm³