100 mL each of 1M AgNO₃ and 1M NaCl are mixed .The nitrate ion concentration in the resulting solution is: 

CONCEPT:

Mixing Solutions and Precipitation

• When solutions of AgNO₃ and NaCl are mixed, a precipitation reaction occurs because AgCl is insoluble in water.
• The reaction is as follows:

  AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)

• In this reaction:
  • Ag⁺ ions react with Cl^- ions to form the precipitate AgCl.
  • The other ions, NO₃^- and Na⁺, remain in the solution as spectator ions.
• To calculate the concentration of nitrate ions in the resulting solution, consider the total volume and the moles of NO₃^- ions present.

EXPLANATION:

• Initially, 100 mL of 1 M AgNO₃ is mixed with 100 mL of 1 M NaCl.
• From the AgNO₃ solution:
  • 1 M AgNO₃ means 1 mole of AgNO₃ is present in 1 L of solution.
  • Thus, in 100 mL (0.1 L) of AgNO₃, the moles of AgNO₃ are:

    Moles of AgNO₃ = 1 × 0.1 = 0.1 moles

• Since each AgNO₃ molecule provides one NO₃^- ion, the moles of NO₃^- ions are also 0.1 moles.
• The total volume of the solution after mixing is:

  Total volume = 100 mL + 100 mL = 200 mL = 0.2 L

• The concentration of NO₃^- ions in the resulting solution is:

  [NO₃^-] = Moles of NO₃^- / Total volume

  [NO₃^-] = 0.1 / 0.2 = 0.5 M

Therefore, the nitrate ion concentration in the resulting solution is 0.5 M.