High pCO₂, low pH, high H⁺ concentration and high temperature favour dissociation of O₂ from haemoglobin.

Factors that do not favour the formation of oxyhaemoglobin:


- High pCO2 (partial pressure of carbon dioxide) in the blood indicates a higher concentration of carbon dioxide.
- Low pH indicates acidity in the blood.
- Both high pCO2 and low pH are indicators of a higher concentration of carbonic acid (H2CO3) in the blood.
- Carbonic acid dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
- The presence of hydrogen ions (H+) in the blood leads to a decrease in pH, making it more acidic.
- High levels of carbon dioxide and low pH indicate that the body is producing more carbonic acid due to increased metabolic activity or respiratory problems.
- These conditions do not favour the formation of oxyhaemoglobin because the increased concentration of hydrogen ions (H+) interferes with the binding of oxygen (O2) to haemoglobin (Hb).
- The affinity between haemoglobin and oxygen decreases in an acidic environment, making it difficult for oxygen to bind to haemoglobin and form oxyhaemoglobin.


- High pO2 (partial pressure of oxygen) indicates a higher concentration of oxygen in the blood.
- High pH indicates alkalinity in the blood.
- Both high pO2 and high pH are not directly related to the formation of oxyhaemoglobin.
- High pO2 only indicates the availability of oxygen in the blood for binding with haemoglobin.
- High pH indicates a more basic environment, which does not directly affect the binding of oxygen to haemoglobin.
- Therefore, high pO2 and high pH do not hinder the formation of oxyhaemoglobin.


- Lesser H (hydrogen ion) concentration refers to a lower concentration of acidic ions in the blood.
- Lower temperature indicates a decrease in the overall temperature of the blood.
- Both lesser H concentration and lower temperature do not directly hinder the formation of oxyhaemoglobin.
- Lesser H concentration does not interfere with the binding of oxygen to haemoglobin.
- Lower temperature may slightly increase the affinity between haemoglobin and oxygen, making it easier for oxygen to bind to haemoglobin and form oxyhaemoglobin.
- Therefore, lesser H concentration and lower temperature do not hinder the formation of oxyhaemoglobin.


- Low pCO2 indicates a lower concentration of carbon dioxide in the blood.
- Low H concentration refers to a lower concentration of hydrogen ions (H+) in the blood, indicating a more basic environment.
- Both low pCO2 and low H concentration do not directly hinder the formation of oxyhaemoglobin.
- Low pCO2 indicates a lower production of carbonic acid and a decrease in the concentration of hydrogen ions (H+) in the blood.
- Low H concentration in a basic environment does not interfere with the binding of oxygen to haemoglobin.
- Therefore, low pCO2 and low H concentration do not hinder the formation of oxyhaemoglobin.

Conclusion:
- Among the given options, high pCO2 and low pH (option A) do not favour the formation of oxyhaemoglobin.
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