Final answer:
To write the formula for the conjugate acid, add a hydrogen ion (H+) to a base, increasing its charge by one. Acids must be electrically neutral, balanced by the H+ ions. For example, the conjugate acid of SO4^2- is H2SO4 using the crisscross method.
Step-by-step explanation:
To write the formula for the conjugate acid of a base, one needs to add a hydrogen ion (H+) to the base, which increases the charge by one. For instance, the conjugate acid of the sulfate ion (SO42-) is bisulfate (HSO4-). When acids lose a proton (H+), they form their conjugate base, decreasing the charge by one. The acid formulation is based on the principle that the acid must be electrically neutral, with the positive charges of hydrogen ions (H+) balancing out the negative charges of the anion.
Here's an example using sulfuric acid:
1. Identify the charge on the polyatomic ion, sulfate (SO42-).
2. Determine the number of hydrogen ions required to balance the charge, which is two (H+).
3. Apply the crisscross method to obtain the correct formula for the acid, resulting in H2SO4.
4. Write the final formula without subscripts for single atoms or ions, so you write H2SO4 as it is.