Arsenic poisoning is a serious problem in many parts of the world. When arsenic poisoning occurs, arsenic binds to proteins and eventually causes cellular damage. This leads to a variety of symptoms in humans including exhaustion, muscle weakness, organ failure, and cancer. Arsenic poisoning is commonly treated with a drug called dimercaprol (or BAL) that binds arsenic, which sets up a competing equilibrium within the body. Once arsenic reacts to form a complex with BAL, it can be excreted from the body. Arsenic-protein complex Arsenic + proteins + BAL Arsenic-BAL complex
How does treatment with BAL affect the equilibrium shown above?
A) Adding BAL does not affect the equilibrium.
B) Adding BAL pushes the reaction to the left.
C) Adding BAL pushes the reaction to the right.
D) Adding BAL causes less arsenic-BAL to be made.
E) Adding BAL causes more arsenic-protein complex to be made.

Question

Arsenic poisoning is a serious problem in many parts of the world. When arsenic poisoning occurs, arsenic binds to proteins and eventually causes cellular damage. This leads to a variety of symptoms in humans including exhaustion, muscle weakness, organ failure, and cancer. Arsenic poisoning is commonly treated with a drug called dimercaprol (or BAL) that binds arsenic, which sets up a competing equilibrium within the body. Once arsenic reacts to form a complex with BAL, it can be excreted from the body. Arsenic-protein complex  Arsenic + proteins + BAL  Arsenic-BAL complex
How does treatment with BAL affect the equilibrium shown above?
A) Adding BAL does not affect the equilibrium. 
B) Adding BAL pushes the reaction to the left. 
C) Adding BAL pushes the reaction to the right. 
D) Adding BAL causes less arsenic-BAL to be made. 
E) Adding BAL causes more arsenic-protein complex to be made.

Quizplus · Accepted Answer

Adding BAL pushes the equilibrium to the right, as the BAL binds to the arsenic, removing it from the equation and causing more arsenic to react with the protein to form the arsenic-protein complex. This allows for more arsenic to be excreted from the body through the urine, leading to the treatment of arsenic poisoning.

Arsenic Poisoning Is a Serious Problem in Many Parts of the World