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Question: 0.1g \(KI{O_3}\) and excess \(KI\) when treated with HCL, the iodine is liberated. The liberated iod...

0.1g KIO3KI{O_3} and excess KIKI when treated with HCL, the iodine is liberated. The liberated iodine required 45ml sodium thiosulphate for titration. The molarity of sodium thiosulphate will be equivalent to:
(A) 0.252M
(B) 0.126M
(C) 0.0313M
(D) 0.0623M

Explanation

Solution

Hint: HCl stands for hydrochloric acid. Hydrochloric acid does count in the list of oxidizing agents in fact its hydrogen ions (H+) is used as electron donor to other molecules and atoms. Hydrochloric acid has a typical suffocating smell.

Complete step by step solution:
Given, 0.1gKIO3,molar mass of KIO3=214 ∴molar of KIO3=given massmolar mass=0.1214=0.00047moles now, KIO3+5KI+3H2SO4⇌3K2SO4+3H2O+3I2↑ I2is liberated from KIO3, ⇒0.00047÷2=0.000235 0.1gKI{O_3},molar{\text{ mass of }}KI{O_3} = 214 \\\ \therefore molar{\text{ of }}KI{O_3} = \dfrac{{given{\text{ mass}}}}{{molar{\text{ mass}}}} = \dfrac{{0.1}}{{214}} = 0.00047moles \\\ now, \\\ KI{O_3} + 5KI + 3{H_2}S{O_4} \rightleftharpoons 3{K_2}S{O_4} + 3{H_2}O + 3{I_{_2}} \uparrow \\\ {I_2}is{\text{ liberated from }}KI{O_3}, \\\ \Rightarrow 0.00047 \div 2 = 0.000235 \\\
Now, moles of KI reacting;
⇒\Rightarrow0.00047×\times5 = 0.000235
Moles ofI2{I_2} produced from KI
⇒\Rightarrow 0.000235÷\div 2 = 0.0001175
Total moles of I2{I_2}= 0.000235 + 0.0001175 = 0.000141
⇒\Rightarrow0.000141 equivalent of I2{I_2}
Equivalent of thiosulphate = 2 ×\times0.000141
⇒\Rightarrow0.000282
MOLARITY =
molarity=0.000282×100045 ⇒0.00626M molarity = 0.000282 \times \dfrac{{1000}}{{45}} \\\ \Rightarrow 0.00626M \\\
Therefore option (D) is the right answer.

MOLARITY= it is defined as the moles of complete substance per litre of solution.
HCl has a concentration of 12.19 mol/litre. Moreover the molar mass of HCl is 36.458 g/mol. The strongest oxidation agent is Fluorine and the weakest oxidizing agent is Li+. The HCl is the weakest reducing agent this is because its electron will accept the chlorine from chloride atoms i.e. (Cl-). Hydrochloric acid donates protons. Where as in dilute hydrochloric acids is used as extraction of basic substances for the removal of basic impurities. From all these acids the carbonate acid is the most powerful acid and first it used to term as superacid.

Note: Molarity is more convenient to use in experiments with significant temperature changes because the volume of solution increases with temperature, and heating causes molarity to decrease. However, since molarity is based on masses rather than the volumes, thus molarity remains unchanged.