[Cu(H_2O)_4]^{2+} + H_2O. Write the equation for the following species acting as an acid.
Answer (2)
The chemical species [ C u ( H 2 O ) 4 ] 2 + H 2 O acts as an acid by donating a proton.
The equation for the deprotonation of the complex ion is: [ C u ( H 2 O ) 4 ] 2 + ( a q ) ⇌ [ C u ( H 2 O ) 3 ( O H ) ] + ( a q ) + H + ( a q )
One of the coordinated water molecules loses a proton, forming a hydroxide ligand and releasing a hydrogen ion.
The final equation represents the acidic behavior of the given copper complex in water. [ C u ( H 2 O ) 4 ] 2 + ( a q ) ⇌ [ C u ( H 2 O ) 3 ( O H ) ] + ( a q ) + H + ( a q )
Explanation
Understanding the Problem The chemical species given is [ C u ( H 2 O ) 4 ] 2 + H 2 O . We need to write the equation for this species acting as an acid. This means we need to show the deprotonation of the complex ion, where it releases a proton ( H + ) and forms its conjugate base.
Writing the Acidic Equation The copper ion, C u 2 + , is surrounded by water ligands. One of these water ligands can donate a proton, acting as an acid. The equation for this process is:
[ C u ( H 2 O ) 4 ] 2 + ( a q ) ⇌ [ C u ( H 2 O ) 3 ( O H ) ] + ( a q ) + H + ( a q )
In this equation, one of the water ligands ( H 2 O ) loses a proton ( H + ), becoming a hydroxide ion ( O H − ) coordinated to the copper ion. The overall charge of the complex ion decreases by one because a proton ( H + ) with a +1 charge is released.
Final Answer Therefore, the equation for the given species acting as an acid is:
[ C u ( H 2 O ) 4 ] 2 + ( a q ) ⇌ [ C u ( H 2 O ) 3 ( O H ) ] + ( a q ) + H + ( a q )
Examples
This concept is crucial in understanding the behavior of metal ions in aqueous solutions, which is relevant in various fields such as environmental chemistry, biochemistry, and coordination chemistry. For example, the acidity of metal aqua ions affects the solubility and bioavailability of metals in natural waters and biological systems. Understanding how metal ions like copper act as acids helps predict their behavior in different chemical environments and is essential for designing effective water treatment processes or understanding enzyme mechanisms.
The species [ C u ( H 2 O ) 4 ] 2 + acts as an acid by donating a proton to form [ C u ( H 2 O ) 3 ( O H ) ] + and H + . The equation for this reaction is: [ C u ( H 2 O ) 4 ] 2 + ( a q ) ⇌ [ C u ( H 2 O ) 3 ( O H ) ] + ( a q ) + H + ( a q ) . This highlights the acidic nature of the copper complex when dissolved in water.
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