Identify A, B, and C in this Lead ( $Pb$ ) reaction sequence: 1. $PbCl_2 + K_2CrO_4 \rightarrow \mathbf{A} (\text{Yellow}) + KCl$ 2. $\mathbf{A} + NaOH (\text{excess}) \rightarrow \mathbf{B} (\text{Soluble})$ 3. $PbSO_4 + CH_3COONH_4 \rightarrow \mathbf{C} (\text{Soluble}) + (NH_4)_2SO_4$

Why does the white precipitate of $PbSO_4$ dissolve when Ammonium Acetate ( $CH_3COONH_4$ ) is added?

Compare the Hybridization and Geometry of: 1. $[NiCl_4]^{2-}$ 2. $[Ni(CN)_4]^{2-}$ 3. $[Ni(CO)_4]$

Predict the geometry of $[PtCl_4]^{2-}$ and $[PdCl_4]^{2-}$ . (Hint: How does it differ from $[NiCl_4]^{2-}$ ?)

Which of the following molecules are Tetrahedral? $SF_4, \ XeF_4, \ SeF_4, \ [NiCl_4]^{2-}, \ CH_4$