Question

which rule should be followed when naming binary acids?
use a prefix for the number of hydrogens.
start the name with hydro-.
change -ate to -ic.
change -ous to -ite.

Explanation:

Binary acids are named by starting the name with "hydro -" followed by the root of the non - hydrogen element and ending with the suffix "-ic acid". For example, HCl is hydrochloric acid. The rule of starting the name with "hydro -" is correct among the given options.

Answer:

Start the name with hydro-.