Answer: The molarity of hydroiodic acid in the titration is 0.485 M.
Explanation:
To calculate the molarity of acid, we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]HI[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is [tex]Ca(OH)_2[/tex]
We are given:
[tex]n_1=1\\M_1=?M\\V_1=20.3mL\\n_2=2\\M_2=0.186M\\V_2=26.5mL[/tex]
Putting values in above equation, we get:
[tex]1\times M_1\times 20.3=2\times 0.186\times 26.5\\\\M_1=0.485M[/tex]
Hence, the molarity of hydroiodic acid is 0.485M.