Question

20)

Consider the titration of a 26.8 −mL sample of 0.115 M RbOH with 0.105 M HCl. Determine each of the following.

Part A

the initial pH

Express your answer using two decimal places.

Part B

the volume of added acid required to reach the equivalence point

Part C

the pH at 5.2 mL of added acid

Express your answer using two decimal places.

Part D

the pH at the equivalence point

Express your answer as a whole number.

Part E

the pH after adding 6.0 mL of acid beyond the equivalence point

Express your answer using two decimal places.

Answer 1

20)

Consider the titration of a 26.8 −mL sample of 0.115 M RbOH with 0.105 M HCl. Determine each of the following.

Part A

the initial pH

Express your answer using two decimal places.

Ans:

Part B

the volume of added acid required to reach the equivalence point

Ans :

Part C

the pH at 5.2 mL of added acid

Express your answer using two decimal places.

Ans:

The number of mmol of RbOH

The number of mmol of HCl added

0.546 mmol of HCl will neutralise 0.546 mmol of RbOH. of RbOH will remain.

Total volume

Part D

the pH at the equivalence point is 7. The solution is neutral with equal concentration of hydrogen ions and hydroxide ions. This is true for the titration of any strong acid with any strong base.

Express your answer as a whole number.

Part E

the pH after adding 6.0 mL of acid beyond the equivalence point

Express your answer using two decimal places.

Ans:

Volume of HCl required to reach equivalence point is 29.4 mL.

Total volume

The number of mmol of excess HCl added