Question

The formula for the selenate ion is seo42−. predict the formula for selenic acid.

Answer 1

The formula for selenic acid is H2SeO4.

Step-by-step explanation:

Selenic acid is an oxoacid of selenium, which means that it contains selenium and oxygen atoms bonded together in a compound that also contains hydrogen atoms. The selenate ion, which has the formula SeO42-, is an ion that contains selenium and oxygen atoms bonded together. Based on these facts, we can predict that the formula for selenic acid will contain selenium, oxygen, and hydrogen atoms.

To determine the specific ratio of atoms in the formula for selenic acid, we can look at the valences of the elements involved. The valence of an element is the number of bonds it can form with other atoms. Selenium has a valence of 6, oxygen has a valence of 2, and hydrogen has a valence of 1.

Since selenium has a valence of 6, it can bond with 6 oxygen atoms. This means that selenic acid will contain at least one selenium atom bonded to 6 oxygen atoms. In addition, selenic acid will contain hydrogen atoms, which can bond with oxygen atoms. Based on these considerations, we can predict that the formula for selenic acid will be H2SeO4, which contains one selenium atom bonded to 6 oxygen atoms and 2 hydrogen atoms.

Answer 2

The formula for selenic acid, derived from the selenate ion SeO4^2-, is H2SeO4. In the case of a compound between sodium (Na+) and sulfide (S^2-), the resulting formula of the ionic compound is Na2S.

Step-by-step explanation:

The formula for selenic acid can be predicted by knowing that selenic acid is the acid form of the selenate ion, SeO42-. To find the formula for selenic acid, you would need to add two hydrogen ions (H+) to the selenate ion. Hence, the formula for selenic acid is H2SeO4.

Similarly, when determining the formula of an ionic compound formed between the sodium cation (Na+) and the sulfide anion (S2-), we seek a neutral compound. Each sodium ion has a charge of +1, and each sulfide ion has a charge of -2. To balance these charges, two sodium ions would be needed for every sulfide ion to create a neutral compound. Therefore, the formula for the compound would be Na2S.