identify the double displacement reactions among the following: 1. kcl (aq) agno3 (aq) → agcl (s) kno3 (aq) 2. na2so4 (aq) bacl2 (aq) → baso4 (s) 2 nacl (aq) 3. h2so4 (aq) 2 naoh (aq) → na2so4 (aq) 2 h2o (l)