Select from the response list the compound or ion that best fits the description: conjugate acid of $HPO _4{ }^{2-}$.
$PO _4{ }^{3-}$
$H _2 PO _4^{-}$
$H _3 PO _4$
$HPO _4{ }^{2-}$
Answer (2)
The problem requires identifying the conjugate acid of H P O 4 2 − .
A conjugate acid is formed by adding a proton ( H + ) to the base.
Adding a proton to H P O 4 2 − results in H 2 P O 4 − .
Therefore, the conjugate acid of H P O 4 2 − is H 2 P O 4 − .
Explanation
Understanding the Problem The problem asks us to identify the conjugate acid of the H P O 4 2 − ion from the given list of options. The conjugate acid is formed when a base accepts a proton ( H + ).
Finding the Conjugate Acid To find the conjugate acid of H P O 4 2 − , we need to add a proton ( H + ) to it: H P O 4 2 − + H + → H 2 P O 4 − This means the conjugate acid of H P O 4 2 − is H 2 P O 4 − .
Selecting the Correct Option Now, we check the given options to see which one matches our result. The options are: P O 4 3 − H 2 P O 4 − H 3 P O 4 H P O 4 2 − The correct option is H 2 P O 4 − .
Final Answer Therefore, the conjugate acid of H P O 4 2 − is H 2 P O 4 − .
Examples
In chemistry, understanding conjugate acids and bases is crucial for predicting how reactions will proceed, especially in biological systems. For example, phosphate buffers, like the H P O 4 2 − / H 2 P O 4 − system, are essential for maintaining the pH of blood. The H P O 4 2 − ion can accept a proton to become H 2 P O 4 − , helping to neutralize excess acid in the bloodstream and maintain a stable pH level. This buffering action is vital for the proper functioning of enzymes and other biological processes.
The conjugate acid of H P O 4 2 − is formed by adding a proton, yielding H 2 P O 4 − . Therefore, from the options provided, the correct choice is H 2 P O 4 − .
;
