Answer to Question #119239 in Chemistry for Medtech Girlsz

Question

2. What is the molar concentration of a AgNO3 solution if 16.35-mL react with:
a) 0.3017-g KIO3 ANSWER: 0.08623 M AgNO3
b) 12.33 mL of 0.02149 M K4Fe(CN)6 ANSWER: 0.06482 M AgNO3
Molar masses: KIO3 = 214.0 K4Fe(CN)6 = 368.4

Answer 1

Solution:

a)

The balanced chemical equation:

AgNO₃ + KIO₃ = AgIO₃ + KNO₃

According to the chemical equation: n(AgNO₃) = n(KIO₃)

Moles of KIO₃ = n(KIO₃) = Mass of KIO₃ / Molar mass of KIO₃

n(KIO₃) = (0.3017 g) / (214.0 g/mol) = 0.00141 mol

n(AgNO₃) = n(KIO₃) = 0.00141 mol

Molarity of AgNO₃ = Moles of AgNO₃ / Volume of solution

Molarity of AgNO₃ = (0.00141 mol) / (0.01635 L) = 0.08624 mol/L = 0.08624 M

Molarity of AgNO₃ is 0.08624 M.

Answer (a): The molar concentration of a AgNO₃ solution is 0.08624 M.

b)

The balanced chemical equation:

4AgNO₃ + K₄[Fe(CN)₆] = Ag₄[Fe(CN)₆] + KNO₃

According to the chemical equation: n(AgNO₃)/4 = n(K₄[Fe(CN)₆])

Moles of K₄[Fe(CN)₆] = n(K₄[Fe(CN)₆]) = Molarity of K₄[Fe(CN)₆] × Volume of solution

n(K₄[Fe(CN)₆]) = (0.02149 M) × (0.01233 L) = 0.000265 mol

n(AgNO₃) = 4 × n(K₄[Fe(CN)₆]) = 4 × (0.000265 mol) = 0.00106 mol

Molarity of AgNO₃ = Moles of AgNO₃ / Volume of solution

Molarity of AgNO₃ = (0.00106 mol) / (0.01635 L) = 0.06483 mol/L = 0.06483 M

Molarity of AgNO₃ is 0.06483 M.

Answer (b): The molar concentration of a AgNO₃ solution is 0.06483 M.