Question

problems:

1. a student performed an experiment investigating precipitation reactions.

each flask below contains one of the following
each flask below contains one of
solutions...
solutions...
pb(no3)2; nacl; k2co3
agno3; bacl2
when the student combined a sample of solution q with a sample of solution x, a precipitate formed. a
precipitate also formed when samples of solution q and y were combined.
identify solution q
what is the chemical
formula(s) for each
of the 2 precipitates?

Explanation:

Step1: List possible reactions for Q

Q is from {Pb(NO₃)₂, NaCl, K₂CO₃}; X/Y from {AgNO₃, BaCl₂}. Check which Q reacts with both X/Y:

• Pb(NO₃)₂ + AgNO₃: No precipitate (same anion).
• NaCl + BaCl₂: No precipitate (same anion).
• K₂CO₃ + AgNO₃ → Ag₂CO₃↓; K₂CO₃ + BaCl₂ → BaCO₃↓. Both form precipitates. So Q=K₂CO₃.

Step2: Identify precipitates

Reaction 1: K₂CO₃ + 2AgNO₃ → Ag₂CO₃↓ + 2KNO₃ (precipitate: Ag₂CO₃).
Reaction 2: K₂CO₃ + BaCl₂ → BaCO₃↓ + 2KCl (precipitate: BaCO₃).

Answer:

Identify Solution Q: K₂CO₃
Chemical Formulas for the 2 Precipitates: Ag₂CO₃ and BaCO₃