The reaction of lead chromate with NaOH (in hot, excess conditions) results in the formation of a soluble dianionic complex:
PbCrO4 + NaOH (hot, excess) → [Pb(OH)4]2- + Na2CrO4
The product [Pb(OH)4]2- is a dianionic complex with a coordination number of four.
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: