The city of Flint, MI is dealing with an environmental health and safety crisis as lead water pipes throughout the city continue to release lead into the drinking water due a change in the municipal water source.
We know now that lead is poisonous with serious health effects, especially in developing children http://www.cdc.gov/niosh/topics/lead/health.html. However, before 1950 lead was commonly used throughout our communities in water pipes, paint, and other materials. In most cases the lead pipes that remain in older homes and cities and are not currently releasing lead due to corrosion products including the lead carbonate mineral cerrusite. These corrosion products formed quickly after the pipes were installed and now coat the inside of the pipes, preventing further lead release.
The problems in Flint began when they changed from a groundwater source with relatively high pH (8-9) to a surface water source with lower pH (6-7), without adding chemicals to the water that would have stabilized and preserved the corrosion product coatings.
Once the Pb2+ is released via oxidation, it can combine with carbonic acid (H2CO3), bicarbonate ions (HCO3-), or carbonate ions (CO32-) in solution to form cerussite (PbCO3).
Write balanced chemical reactions showing both carbonate speciation boundaries as well as three separate reactions show how cerussite dissolves to release lead into solution in equilibrium with each dissolved carbonate phase. Calculate the log K for each reaction at standard state.
I have the three equations for the formations of cerrusite but I have no idea what the reactions for carbonate speciation boundries
The city of Flint, MI is dealing with an environmental health and safety crisis as lead water pipes throughout the city continue to release lead into the drinking water due a change in the municipal water source.
We know now that lead is poisonous with serious health effects, especially in developing children http://www.cdc.gov/niosh/topics/lead/health.html. However, before 1950 lead was commonly used throughout our communities in water pipes, paint, and other materials. In most cases the lead pipes that remain in older homes and cities and are not currently releasing lead due to corrosion products including the lead carbonate mineral cerrusite. These corrosion products formed quickly after the pipes were installed and now coat the inside of the pipes, preventing further lead release.
The problems in Flint began when they changed from a groundwater source with relatively high pH (8-9) to a surface water source with lower pH (6-7), without adding chemicals to the water that would have stabilized and preserved the corrosion product coatings.
Once the Pb2+ is released via oxidation, it can combine with carbonic acid (H2CO3), bicarbonate ions (HCO3-), or carbonate ions (CO32-) in solution to form cerussite (PbCO3).
Write balanced chemical reactions showing both carbonate speciation boundaries as well as three separate reactions show how cerussite dissolves to release lead into solution in equilibrium with each dissolved carbonate phase. Calculate the log K for each reaction at standard state.
I have the three equations for the formations of cerrusite but I have no idea what the reactions for carbonate speciation boundries
Related textbook solutions
Basic Chemistry
Principles of Chemistry Molecular Approach
Principles of Chemistry Molecular Approach
Chemistry: Structure and Properties
Chemistry: A Molecular Approach
Chemistry: A Molecular Approach
Principles of Chemistry: A Molecular Approach
